Very good for the use I bought it for. I use it in the store's warehouse to notify me when a customer enters the store. Many strong melodies, good signal up to 20 meters with two walls in between

Very good product, it has powerful and pleasant sound. The transmitter does not have batteries, it plugs into the socket so you don't waste batteries, the receiver has batteries. It is simple, easy to use. I have nothing else to add.