Description:
Turn up the receiver's switch to "on" position, it will beep constantly('dee...dee...'), and push one button on the transmitter, the receiver will stop beep after matching.
When you want to find the lost keys or other things, just press the matching button on the transmitter(when the indicator light off), and the receiver will sound alarm with 0.5-2 seconds(according to the distance), the alarm will last for 4 seconds and then stop.

Specifications:
External material: plastic
Design: RF Wireless Technology
Power: Receiver: 1 x CR2032 Button Cell Battery(included)
          Transmitter: 1 x CR1632 Button Cell Battery(included)
Size: Receiver: 5.2 x 3.2 x 1.3cm
       Transmitter: 6.5 x 3.2 x 1.1cm
Indicator light: red

Package included:  
1 x Transmitter
2 x  Receiver