AliMed Sensor Cushion Alarm sounds when embedded pressure sensor detects patient attempting to leave chair. This cushion comes with the same alarm unit as does our AliMed(R) Pressure Sensor Pad, but differs because the sensor is sandwiched between 3" of fire-retardant cushioning foam. A holding bracket for the alarm box is included to keep it out of patient"s way. (Mount bracket on back or side of seat.) Cushion is upholstered in waterproof, brushed vinyl with two ties for attachment to the wheelchair seat. Includes 9V battery, universal mounting bracket and AliTie(tm) to keep excess electrical cording neatly tied. 17" x 16" x 3" cushion fits both 16" and 18"W wheelchairs. The alarm has an on/off switch and the volume can be on soft (85 dB) or loud (100 dB). Unit features alarm and chime tone and low battery warning.