The Chairpro UnderSeat Alarm is a wandering patient system and seating safety monitor designed for people with lower extremity, mobility and balance disabilities and other who use wheelchairs and have Alzheimer's disease, dementia or other cognitive disabilities. The ChairPro sounds an alarm when the user leaves the chair without assistance. Designed to fit all sling-seat wheelchairs up to 22-inches wide, this sensor alarm activates when the user rises and automatically resets once the person is reseated. It is effective with or without seat cushion. Because of its under-seat placement, the alarm is protected against incontinence, wear-and-tear, and tampering. POWER: Uses 1 9-volt battery (included). WEIGHT: 2.0 pounds. WARRANTY: Sensor and alarm are guaranteed for 1 year.