SincereetaliProduct Description 1. Press the button, super learning code can freely learn to match, can be unlimited matching receiver and button. 2. The transmitter without screw chuck design to achieve waterproof and dustproof. 3. The wireless signal will be affected by obstacles. The more obstacles, the more serious the signal loss. Description: 1. The receiver can be hung on the wall or stand on the table. The button can be fixed to a wall or door using double-sided tape or screws. Specifications: Model: A20 Power supply mode: 12V23A Power supply voltage: 110-220 (V) Ringtone: 36 Power consumption: 1 (W) Scope of application: 200M open Type: wireless doorbell Color: black Package Included: 1 x Wireless Doorbell Set Notes: 1. Due to the difference between different monitors, the picture may not reflect the actual color of the item. We guarantee the style is the same as shown in the pictures. 2. Please allow slight dimension difference due to different manual measurement.