беспроводной дверной звонок

wireless doorbells with auto-match code function. 1.Battery powered using 3*1.5V AAA for receiver,1*12V 23A for button. 2The range up to 100 meters, 16.17.25.36 tunes for choosing. 3.Volume adjustable :low and high. 4.Three patterns available: Ring Only, Light flash only,or combination of Ring and Light Flash. 5.Power saving battery of both receiver and transmitter can be used for 12 months. 6.CE and Rohs standard meet. 7. Auto match code function which ensure a unique connection between the receiver and sender and avoid disruption. 8. Led indication light in the receiver which make easy for Dh