1) The battery life of the button is up to 1 years (calculated 10 times a day). 2) Long-distance open and barrier-free 300 meters/984FT has strong penetration performance, and indoor obstacles are about 20~60 meters. 3) Equipped with 60 pieces of music, 5 levels of volume, and the receiver has up and down song selection keys, making the operation more convenient! 4) The host has a large metal speaker, which sounds pleasant to the ear! The volume is about 85-97dB, 5) Application occasions: Used as a wireless doorbell or call reminder in homes, villas, schools, companies, hospitals and other places. Supports the use of multiple sets of doorbells, any button, the receiver ringtone sound, and each button can be set with a different ringtone to distinguish visitors. Colour:White Material:ABS+Electronics Power Supply: 3 x AAA batteries(Not included batteries) Package Contents: 1 * receiver 2 * transmitter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.