Description Package Included: 1 x Remote Controller 1 x Wireless Musical Doorbell 1 x Double-sided Adhesive Tape Features: Doorbell Receiver Size: Approx.10.3x6.2x3cm/ 4.06x2.44x1.18" Remote Control Size: Approx. 7.8x4.4x1.7cm/ 3.01x1.73x0.67" Doorbell Power Supply: 2 x AA batteries (Not included) Remote Control Power Supply: 1 x 12V/23A battery (Not included) Working Frequency: 315MHZ/ 433MHZ Effective Distance: Approx. 15-20m/ 49.21-65.62ft (Home) Effective Distance: Approx. 20-30m/ 65.62-98.43ft (Open areas) Power consumption: 15W Voltage: 9V 36 melody music Overlong remote could be 100 meters, the sound of signal reach a once at your will, even though it is used in high building, villa or other complex building The door bell can be installed at random the button can be fixed or pasted. It is application in bedroom, office, restaurant, factory, dormitory or any other place where need help. You won't miss any visitors any more