Shake&Vibrate Bed Shaker alerts a sleeping or hearing impaired person by its powerful vibration. To wake a sleeper, place the bed shaker under the sleeper's pillow, or between the bed mattress and its box spring. Very strong vibrations help to alert sleepers or difficult-to-alert patients. Very effective for waking deep sleepers when used with the DryBuddyFLEX bedwetting alarm. Automatic shut off.