Wireless Doorbell With 1 push button transmitter and 2 plug in receivers smart door bell chime perfect for small 2-story homes or large apartments. If you need can add more push button transmitter and plug in receivers easily. Door bell chime with 58 Melodies & 5 Level Volume meet your different need for tunes and volume. Ultra-low power consumption design, sustainable use of Energy.work in -30°C to 70°C suit for different place.