Wireless chime X800 and transmitter X10R set, convenient with a waterproof structure and a 100m communication range. You can choose from three receiving options: sound only, light only, or sound and light, making it usable for those with hearing impairments! There are 16 different chime sounds, and the volume is adjustable, selectable in the settings! With a 256-pattern digital ID code system, there is almost no interference. - Brand: REVEK - Model: Chime X800 - Model: Transmitter X10R - Function: Wireless Chime - Range: 100m - Included: Instruction manual, screws (Batteries not included) Receiver: 3 AA alkaline batteries Transmitter: 2 AAA alkaline batteries Please prepare batteries separately. I used this for about a year in an apartment without a chime. The transmitter is discolored, but there are no malfunctions. I have confirmed the operation. When set to sound and light, the sound is a little scratchy, but there are no particular problems with sound only or light only. You can also adjust the volume and sound, making it a convenient chime! Thank you for viewing.