Safetysure Wheelchair Board 18 L x 16 W Mattress Overlays Toppers Saturation Sound Pressure Level (SSPL) 14272 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 Tube 1 Penlight 1 First Aid Handbook 18 L x 16 L * Provides flat sitting surface and eliminates the hammock effect associated with traditional wheelchair seats * Made of lacquered finished plywood * Corners and sides are rounded to prevent chipping * Makes an excellent sitting surface when combined with a pressure relief cushion * Splinter free plywood * Weight capcity : 300 lbs *