The G-5 Custom Built Cushion is an alternating air pressure flotation seat cushion designed to prevent pressure sores for people with lower extremity or mobility disabilities, spinal cord injury and others who use a wheelchair. This system features computer controlled pressure management that increases and decreases air pressure in the cushion as needed. Each cushion is custom built to fit the user and wheelchair. POWER: Uses rechargeable battery with 70 to 80 hours running time and 12 to 20 hours reserve time. An audible warning indicates when the unit is running on reserve power. WARRANTY: One year unconditional warranty.