The product is a V006 315MHz 12V 15mA 20 times/Day 38 Songs Supply for Choice 50M Wireless Door Chime, please refer to the below details.

Description
V006 wireless doorbell DC
It can remind you there have someone visit your. you can install the main unit separate from the door in 30ms.
The work voltage of the receiver IS DC3V ,Batteries Model:AA R6P×2
Static electricity of the receiver IS 0.45mA(Ultra-low power ,can extend battery life)
Work Frequency 315MHz   
Remote Control /Incept Distance IS 40m(in open air)
Work Voltage of the Emitter is 12V(Battery Model is 23A12V)
Work Electricity of the Emitter is 15mA(20 times a day by calculating,a high quality
battery can use for a year)   
LED Indicator is press the send button,Emitter work and the receiver receive the order
and then send out the beautiful music reminded you the VIP visit, the blue-ray  LED of
the receiver will regular flash along with the music.
Music source is 38songs supply for choice, Use the External button "up/down"to finish.
(the music include Asia,Europe,Americas famous songs,also has 10 songs of Arab Music
Concert which the Middle East customers' like) 
The function of volume regulate is high,middle,low three volume can choice,Use the
External switch(or button)to finish.