Heath/Zenith SL-7366-02 Wireless Plug-In Door Chime Kit with Molded Plastic Cover, White

They work fine. You just have to know how to use them.
I own three of these. They seem to last about 5-10 years and then the receiver stops working, so they cost about $3 per year.I use one doorbell and then three receivers, all set to the same code. That allows the three receivers to ring at the same time as the single doorbell button is pushed. You can hear at least one of them all over the property.To those who claim they are having problems:1. There is a BATTERY in the transmitter. Note that although you plug in the receiver, you don’t plug the transmitter in anywhere. That’s because it is BATTERY powered. When it stops working or becomes unreliable, the battery needs replacing. Replace the battery in the button. It will magically start to work again… BUT…2. Only if the battery is in correctly. Not working? Turn it around the other way: you have positive and negative switched. The slot looks like you should put the battery in one way but that way is wrong. Turn it around. I make that mistake every time I replace the battery, so people stating that they even tried replacing the battery probably put it in backwards like I always do. Just put the battery in and push the button. If nothing happens, turn it around and try it again. It always works for me.3. Now the mysterious ghost rings that wake you up in the middle of the night when no one is there: HELLO, your neighbor just bought one and you are receiving the signal from your neighbor’s doorbell. Change the code on your receiver AND the doorbell button transmitter (they have to match) and the ghosts will “magically” go away.These things work fine. They are cheap so lots of people buy them and that means you need to change the code when you buy them – takes all of 2 minutes – so that when your neighbor buys one you don’t hear his doorbell ringing. They also only last 5-10 years, but that’s what you get for $20.This is the risk of reviews on Amazon: bunches of people who don’t understand the product telling you it doesn’t work when it does. I’ve owned three of them for 10 years and one failed, the others are fine. But I do have to replace the battery every now and then and I did have to change the codes.100 foot range is wishful thinking. With a couple of walls in the way, you’ll get about 25 feet, plus or minus.

Easy iinstalation.
This unit replaced an identical model that was over 10 years old and had seen better days. Glad to have a working unit again.

The bell make nice sound, but the transmitter is not well made
When the door bell kit first arrived, I was so happy because it makes really good sound and installation was really easy. It even came with a battery in the package for the transmitter.However, within weeks of installation, I found the door bell was not working. At first, I thought it was the battery in the transmitter needed to be replaced, but upon closer inspection, I found it was the design of the “battery” holder in the transmitter. The transmitter uses a bend metal instead of spring to hold the batter. When the batter has been in place for awhile, the weight of the batter drove the bend metal down far enough so it was no longer make contact on both ends,so the door bell system was not working. I don’t know how to prop the bend metal so it would not be weighted down by the weight of the battery, so I have to remove the door bell.I ordered the GE 19216 Wireless Door Chime Kit, and with joy I found the transmitter was much better built. It uses a spring instead of a piece of bend metal to prop the batter in place. The door bell itself does not have as nice sound as the Heath system, but at least the transmitter should work better. I will write a review for the GE system in a couple of months.