Unique smart melody design, decoration and practicalityStrong digital anti-interferenceLong-distance remote control (100m long, no obstacles)Creates sweet ding dong original tone or golden melodyNo wiring, no installationWorking temperature: -30 to 60 degree CelsiusFrequency: 315/433MHz+/-0.5MHzQuiescent current: 0.5-1mA Working current: 80-110mAVolume: >= 80dBFor transmitter: Quiescent current: 0mA Working current: less than 10mATransmitting power: <10mWBattery requirements:Transmitter: 12V/23A alkaline batteryReceiver: 2 x 1.5V AA alkaline batteriesBattery life for both receiver and transmitter: one year (standby)Packing: blister, 48 pieces/cartonCarton measurements: 59 x 36 x 39cmMinimum purchase order: 2,000 pieces