Wireless remote control vibration reminder has two parts: vibration receiver and transmitter; small enough for you to carry in the pocket. Press the button on transmitter and the receiver will vibrate to alert. The receiver can be controlled by transmitter from any place within 50m; wireless signal pass through walls, floors and doors. It is also suitable for person with hearing impairment. For example, when you are at the kitchen, you can use remote vibrator to alert him/her at living room to come.

http://www.rfcontrolsystem.com