---
product_id: 7757162
title: "Master Lock Trailer Lock, Black Trailer Tongue Lock 379ATPY"
brand: "master lock"
price: "S$93"
currency: SGD
in_stock: true
reviews_count: 13
category: "Master Lock"
url: https://www.desertcart.sg/products/7757162-master-lock-trailer-lock-black-trailer-tongue-lock-379atpy
store_origin: SG
region: Singapore
---

# Fits 3 coupler sizes (48-59mm) Durable zinc rust-proof build Advanced pick & pry resistance Master Lock Trailer Lock, Black Trailer Tongue Lock 379ATPY

**Brand:** master lock
**Price:** S$93
**Availability:** ✅ In Stock

## Summary

> 🔐 Lock in your peace of mind—because your trailer deserves the best.

## Quick Answers

- **What is this?** Master Lock Trailer Lock, Black Trailer Tongue Lock 379ATPY by master lock
- **How much does it cost?** S$93 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.sg](https://www.desertcart.sg/products/7757162-master-lock-trailer-lock-black-trailer-tongue-lock-379atpy)

## Best For

- master lock enthusiasts

## Why This Product

- Trusted master lock brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Next-Level Theft Defense:** Advanced locking mechanism engineered to resist picking and prying, keeping your trailer invincible.
- • **Built to Brave the Elements:** Zinc construction ensures rust and corrosion resistance, perfect for all-weather protection.
- • **Ready to Use Out of the Box:** Includes two keys and a compact, portable design for effortless locking on the go.
- • **Universal Fit for Ultimate Security:** Seamlessly locks 1-7/8", 2", and 2-5/16" trailer couplers—one lock to rule them all.
- • **Trusted Brand with Lifetime Peace of Mind:** Backed by Master Lock’s Limited Lifetime Warranty—security you can count on.

## Overview

The Master Lock 379ATPY universal trailer hitch coupler lock fits three common coupler sizes (48mm, 51mm, 59mm) and features an advanced locking mechanism that resists picking and prying. Constructed from durable zinc to prevent rust and corrosion, it’s designed for vehicles, trailers, and RVs. This compact, portable lock includes two keys and is backed by a Limited Lifetime Warranty from a trusted industry leader.

## Description

Protect your trailer with the Master Lock 379ATPY Universal Trailer Coupler Lock, a practical towing security solution designed to help prevent unauthorized coupling when your trailer is parked, stored, or left unattended. Built for shoppers looking for a trailer hitch lock that is simple, visible, and compatible with common coupler sizes, this lock helps secure utility trailers, enclosed trailers, RVs, campers, boat trailers, and other towable equipment. This universal design fits 1-7/8 in. (48 mm), 2 in. (51 mm), and most 2-5/16 in. (59 mm) trailer couplers, covering many of the most common towing applications. The coupler lock helps add protection at home, on the road, at a campsite, near a marina, or on a jobsite where trailers may sit unattended between uses. The advanced locking mechanism is engineered to resist picking and prying, giving trailer owners a reliable way to help deter theft and unwanted hitching. Its zinc construction helps resist rust and corrosion for outdoor performance, making it a strong choice for anyone searching for a boat trailer lock, camper hitch lock, RV hitch lock, trailer tongue lock, or lock for trailer hitch security. Compact and easy to keep with your trailer hitch accessories, this keyed trailer coupler lock includes two keys so you can store a spare where it is convenient. Whether you are securing a trailer between weekend trips, protecting equipment during seasonal storage, or adding a visible theft deterrent to your towing setup, the Master Lock 379ATPY offers dependable trailer security from a brand known for trusted locking products.

Review: Solid, Simple Trailer Hitch Lock That Adds Real Peace of Mind - The Master Lock 379ATPY universal trailer hitch lock is a straightforward, effective security solution that does exactly what it’s meant to do. If you’re looking for an easy way to secure a trailer without overthinking the setup, this lock delivers dependable protection with minimal hassle. Fit and compatibility are strong points. The universal design works well across different types of trailers, including RVs, utility trailers, horse trailers, and tool trailers. It fits securely over the coupler and blocks it effectively, preventing anyone from hitching up and towing off your trailer. Once installed, it’s very clear the trailer isn’t going anywhere. Build quality feels solid. The lock has a good weight to it and doesn’t feel thin or easily defeated. While no lock is completely theft-proof, this one is sturdy enough to act as a strong deterrent. It sends a clear message that the trailer is protected and not an easy target, which is often half the battle when it comes to theft prevention. Installation is quick and simple. You don’t need tools or complicated adjustments. It slides into place easily and locks securely. Removing it is just as easy when you’re ready to use the trailer, which makes it convenient for regular use without becoming annoying. The locking mechanism works smoothly. The key turns cleanly without sticking, and the lock opens and closes without feeling gritty or cheap. That’s important for something that may sit outdoors and be exposed to weather. So far, it’s held up well without signs of binding or corrosion. The black finish keeps it discreet while still looking tough and purposeful. It doesn’t draw unnecessary attention, but it’s obvious enough to let would-be thieves know the trailer is secured. It also looks clean and professional, whether the trailer is parked at home, a storage lot, or a campsite. Overall, this Master Lock trailer coupler lock is a reliable, easy-to-use security accessory that does its job well. Strong fit, solid construction, simple operation, and broad compatibility make it a smart choice for protecting trailers of all kinds. If you want added peace of mind without complexity, this is an easy five-star product.
Review: Quality - Works good and more secure then most trailer locks.

## Features

- SECURE TRAILERS, RVS AND TOWING EQUIPMENT: This Master Lock trailer coupler lock helps deter theft by blocking unauthorized coupling, making it a dependable trailer hitch lock for parked trailers, RVs, campers, boat trailers, and utility trailers.
- UNIVERSAL FIT FOR COMMON COUPLER SIZES: Designed to fit 1-7/8 in. (48 mm), 2 in. (51 mm), and most 2-5/16 in. (59 mm) trailer couplers, this trailer tongue lock gives shoppers one versatile solution for multiple towing setups.
- ADVANCED LOCKING SECURITY: The locking mechanism is engineered to resist picking and prying with visible, keyed trailer coupler protection.
- RUST AND CORROSION-RESISTANT ZINC BUILD: Durable zinc construction helps this trailer hitch coupler lock stand up to outdoor storage, changing weather, boat ramps, campsites, jobsites, and everyday driveway use.
- READY TO USE WITH TWO KEYS: Includes one universal trailer coupler lock and two keys, giving you a complete keyed hitch lock solution for securing towing equipment between trips, during storage, or when your trailer is unattended.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B000L9QRE8 |
| Additional Features | Anti-Corrosion, Cut Resistant, Weather Resistant |
| Best Sellers Rank | #2,572 in Automotive ( See Top 100 in Automotive ) #9 in Towing Hitch Locks |
| Brand | Master Lock |
| Brand Name | Master Lock |
| Color | Black |
| Control Method | Touch |
| Controller Type | Hand Control |
| Customer Reviews | 4.6 out of 5 stars 5,983 Reviews |
| Finish Types | Polished |
| Global Trade Identification Number | 00071649229220 |
| Included Components | Unit^Instruction Guide |
| Item Dimensions | 5.1 x 3.5 x 4.6 inches |
| Item Type Name | Universal Trailer Hitch Lock |
| Item Weight | 16 ounces |
| Item dimensions L x W x H | 5.1 x 3.5 x 4.6 inches |
| Lock Type | Key Lock |
| Manufacturer | Master Lock |
| Manufacturer Part Number | 379ATPY |
| Manufacturer Warranty Description | 1 year manufacturer |
| Material | Zinc |
| Material Type | Zinc |
| Model Name | Universal Towing Coupler Lock, Steel |
| Model Number | 379ATPY |
| Number of Items | 1 |
| Number of Packs | 1 |
| Number of Pieces | 1 |
| Recommended Uses For Product | vehicles, trailers, RVs |
| Shape | Rectangular |
| Special Feature | Anti-Corrosion, Cut Resistant, Weather Resistant |
| Style Name | Trailer Hitch Lock |
| UPC | 071649229220 |
| Unit Count | 1 Count |

## Product Details

- **Brand:** Master Lock
- **Item dimensions L x W x H:** 5.1 x 3.5 x 4.6 inches
- **Lock Type:** Key Lock
- **Material:** Zinc
- **Special Feature:** Portable

## Images

![Master Lock Trailer Lock, Black Trailer Tongue Lock 379ATPY - Image 1](https://m.media-amazon.com/images/I/81u7s58ERrL.jpg)
![Master Lock Trailer Lock, Black Trailer Tongue Lock 379ATPY - Image 2](https://m.media-amazon.com/images/I/61cc-WhWJcL.jpg)
![Master Lock Trailer Lock, Black Trailer Tongue Lock 379ATPY - Image 3](https://m.media-amazon.com/images/I/81hOrv-ySuL.jpg)
![Master Lock Trailer Lock, Black Trailer Tongue Lock 379ATPY - Image 4](https://m.media-amazon.com/images/I/91qj2nPog9L.jpg)
![Master Lock Trailer Lock, Black Trailer Tongue Lock 379ATPY - Image 5](https://m.media-amazon.com/images/I/61UPXMuNHeL.jpg)

## Available Options

This product comes in different **Style** options.

## Questions & Answers

**Q: If this does not work on our travel trail is it returnable?**
A: It will it's universal

**Q: Does this fit Airstreams?**
A: I'm not sure what size the hookup is on an Austrian, but it did not fit my 27ft travel trailer, so I use it on my boat trailer instead

**Q: Can these be rekeyed?  I have alot of locks. All on same master lock key**
A: I have 6 of these they can be rekeyed. Try a different lock smith. I would also say to have it keyed with the pad locks so you always only have one key for lots of locks.

**Q: Can I get a key number the same as locks i Have**
A: It would depend on the key # needed. Please feel free to message us with the key # you are looking to match to and we can tell you if it can be done.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Solid, Simple Trailer Hitch Lock That Adds Real Peace of Mind
*by T***M on December 15, 2025*

The Master Lock 379ATPY universal trailer hitch lock is a straightforward, effective security solution that does exactly what it’s meant to do. If you’re looking for an easy way to secure a trailer without overthinking the setup, this lock delivers dependable protection with minimal hassle. Fit and compatibility are strong points. The universal design works well across different types of trailers, including RVs, utility trailers, horse trailers, and tool trailers. It fits securely over the coupler and blocks it effectively, preventing anyone from hitching up and towing off your trailer. Once installed, it’s very clear the trailer isn’t going anywhere. Build quality feels solid. The lock has a good weight to it and doesn’t feel thin or easily defeated. While no lock is completely theft-proof, this one is sturdy enough to act as a strong deterrent. It sends a clear message that the trailer is protected and not an easy target, which is often half the battle when it comes to theft prevention. Installation is quick and simple. You don’t need tools or complicated adjustments. It slides into place easily and locks securely. Removing it is just as easy when you’re ready to use the trailer, which makes it convenient for regular use without becoming annoying. The locking mechanism works smoothly. The key turns cleanly without sticking, and the lock opens and closes without feeling gritty or cheap. That’s important for something that may sit outdoors and be exposed to weather. So far, it’s held up well without signs of binding or corrosion. The black finish keeps it discreet while still looking tough and purposeful. It doesn’t draw unnecessary attention, but it’s obvious enough to let would-be thieves know the trailer is secured. It also looks clean and professional, whether the trailer is parked at home, a storage lot, or a campsite. Overall, this Master Lock trailer coupler lock is a reliable, easy-to-use security accessory that does its job well. Strong fit, solid construction, simple operation, and broad compatibility make it a smart choice for protecting trailers of all kinds. If you want added peace of mind without complexity, this is an easy five-star product.

### ⭐⭐⭐⭐⭐ Quality
*by B***Y on August 17, 2026*

Works good and more secure then most trailer locks.

### ⭐⭐⭐⭐⭐ Master Lock Trailer Coupler Lock 379ATPY - Fits 1-7/8", 2", 2-5/16"
*by L***N on January 2, 2012*

I needed some locks for heavy-duty trailers that use 2-5/16" Bulldog couplers. I had previously had bad luck with Guardian locks, which were more expensive, not as well made, and not backed up by the manufacturer. These Master Lock coupler locks not only appear to be much better than the Guardian locks, they come with a limited lifetime warranty from Master. This lock fits the 2-5/16" Bulldog/Hammerblow couplers (in spite of the fact that this size is not listed) and is a very reasonable price. Fortunately, I cannot say how well they resist thieves' attempts to steal the trailer, but they will certainly provide a substantial deterrent. I bought mine in October 2008 and they have a chrome finish that appears to be excellent. Despite being in the weather all winter in Indiana, they still look and operate as if they were brand new. It looks like Master Lock has switched to the pictured painted or powdercoated finish instead of the chrome plating. I don't know how well the new finish will protect the mechanism compared to my chrome ones, but keep in mind that Master Lock offers a lifetime warranty, which covers operation but not finish. I have never had any trouble installing the lock to the coupler, but I agree that it can be a bit loose when locked. The lock attaches via a number of notches and it's unlikely that you'll find one that is exactly tight. There's no ratchet to help you with this, so you must squeeze the locking mechanism as you turn the key. It's more trouble to write about it than to do it. In spite of the slight looseness, I think someone would have a tough time getting it off the coupler. Regarding sticking tumblers or locking mechanism, I find that I must lubricate all my locks, including these, occasionally. Amazon also sells Master Lock model 379DAT, which has a rubberized coating. I bought one of those recently. It seems to be a bit looser on the coupler, I think because of the coating. Unless you are concerned about the possibility of the coupler's paint chipping from metal-to-metal contact, I would recommend the model 379ATPY over the 379DAT. See Painter Bill's review, dated July 11, 2011. Both of these locks are highly recommended, but especially the 379ATPY.

## Frequently Bought Together

- Master Lock 379ATPY Universal Trailer Hitch Lock , Black
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- RETRUE Trailer Tongue Coupler Lock, Trailer Hitch Lock,Dia 1/4 Inch, 3/4 Inch Span for Tow Boat RV Truck Car's Coupler, Black

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*Product available on Desertcart Singapore*
*Store origin: SG*
*Last updated: 2026-08-30*