[product] wireless doorbell, transmitter + receiver, 52 music, 5 volume adjustment, indicator light, adapt to different groups of people, 20m wireless distance. [Material] ABS material [Detail] The transmitter button battery is powered (excluding the battery), the receiver does not need a battery, just plug it into a power outlet, no need to reset the ringtone after power off. [Remarks] Product size and color may have certain errors with the actual object. Please refer to the actual product for details. [Applicable space] Compatible with companies, families, villas.