Prime-Line U 10547 7/8 In. White-Painted Diecast Vinyl Patio Door Lock with Adjustable (Single Pack)

this item from amazon is amazing..works great and provides a way to lock your sliding door without drilling into frame..using 2 of these prevents door from being broken into.

I like to sleep with my window open a little for fresh air. This allows me to do so and feel safe. The larger one works for the patio door as well. Very pleased.

It works pretty well as an over center cam action clamp. The couple of points I am not so happy about that could be improved are:1. The moving jaw on the back actually has a sawtooth pattern. Eventually this will dig & dent your frame & cause deformation / damage. It would have been better to be smooth & have the jaw faces covered with a soft rubber (or similar) material that would give high surface friction in shear. This would be just as effective & be a lot kinder to the surface.2. the Cam itself is a very mild cam. In other words, I have to unscrew the screw thread about 3 turns to take off the frame or put it back on to get the cam to engage adequately enough to give a secure, but not over tight clamp onto the frame. If it had more of a ramp to it to make a more aggressive cam, it would not need thisConcept is great, execution just needs a little refinement & it is a 5 star product.I did not get paid, reimbursed, of given anything for free (never do as I am not important enough online!) so you are getting my own unbiased, honest opinion & nothing but that. :-)

First thing I noticed upon opening, there is no rubber backing to prevent slippage or damage to the vinyl sliding door. Secondly when I tried to clamp it on it wouldn't tighten in the clamp position. This needs alot of improvement. There going to be returned.

My first review on this was partially in error, I bought this as it is described as a sliding vinyl window lock, and it does work for that but I found that on my windows the screw shaft is too long by about 1 / 16 of an inch, so the jaw will feel secure, but you can push the window with your hand and the lock will slide all the way to open position. Then I noticed on the cardboard that the lock was heat shrink wrapped to, it said "For Patio Doors" So no problem if you need this for a patio door. I will keep the lock because all I have to do is file the end of the clamping screw shaft about 1/8th of an inch, I enjoy stuff like that, keeps me on my toes.

I had to tighten this with a pair of pliers before it would lock down and not slide when I pushed the window against it. I would not recommend this as the only security for vinyl windows if you are really concerned someone can come in through your open windows. I rent so this is kind of the only thing I can depend on but fortunately I don't live in a high-crime area.

These are sturdy and easy to install. I got the 7/8 in. ones. The 1/2 in. says 2-pack so I wrongly assumed the 7/8 in. would also be a 2-pack but there's only one.

I am so glad I stumbled on this lock on Amazon. I was finding nothing that would fit the wide plastic track along my sliding glass door. These work great. I placed one at the top of the door and one at the bottom. The "pointy" side grips the back of the track (the edge pointing towards the glass), so if it mars the finish, it is on the side that can't be seen from inside the house.