A.P.P.Wheelchair & Pump System 18 x 16 x 3 1 4 (Chair Air) Whirpools Accessories Saturation Sound Pressure Level (SSPL) MSHQ 1885 Saturation Sound Pressure Level (SSPL) 118dB Frequency Range 200 4200Hz Total Harmonic Wave Distortion ≤10># td### Reference Test Gain 28±5dB Input noise ≤20dB Sound amplification 45±5dB Max * Durable and easy to maintain these high quality stainless steel units give you a constant supply of temperature consistent HotPacs Includes Pump * Iindividual bladders alternate every 10 minutes to provide a comfortable pressure relieving seating surface * Zippered non skid stretch knit cover is anti microbial and meets California Tech Bulletin #117 for fire retardancy * Dimensions: 18 x 16 x 3 1 4 * Weight: 4 Lbs * 1 year limited (pumps and mattress) and 6 months limited warranties * Portable alternating AC DC pump allows the patient to be totally mobile * Rechargeable battery backup keeps system working for more than 7 hours per charge * Car adapter included * HCPC Code: E0190