Can I buy 2 ring doorbells for my house on the different doors and set different sound for each, so that I can know which door is ringing?

Hi LMartens, Thank you for your attention for Wuloo wireless doorbell chime. Yes, of course! Due to the special anti-interference technology of our doorbell, the same product can be used in the same place without interference. So you can buy 2 sets doorbell and set different ringtones for each set of doorbells that you can know which door is ringing. If you have any other questions, please feel free to contact us, we are always happy to service for you. Have a nice day. Wuloo Customer Service Team

Does the product work for 220 voltage?

Hello, Have a nice day and thank you for your attention for Wuloo products. For your question, we want to tell you: Yes,it does. Sincerely Wuloo

Can i use 5 of these for 5 separate units in an apartment building, or is 3 the limit?

Hi , Thank you for your attention for Wuloo intercom doorbell. For your issue, we recommend you use 3 separate units in an apartment building, since our doobell system has only 3 codes, the indoor unit can work with the intercom system, so they can interfere with each other if they have the same code. If has any other questions, please feel free to contact us, we will assist you within 24 business hours. Have a nice day. Wuloo Customer Service Team

buenas tardes, se puede comunicar por medio de voz entre ellos tres?

Hello, Have a nice day and thank you for your attention for Wuloo products. For your question, we want to tell you: Yes,you can press the talk button to communicate between the outdoor unit and indoor unit when you set them on the same channel,but for the outdoor unit,to save power,outdoor unit will enter sleep mode after 25 seconds unactive,in the sleep mode, the indoor unit can not talk with the outdoor unit, it means every conversation should be start from outdoor unit(visitor). Sincerely Wuloo