Cushion Cover only Roho HP Heavy Duty 20 x 18 Aids to Daily Living Assista Rail * A quarter Jobst Ultrasheer 30 40 ThighHi Assista Rail * A quarter length bed assist rail that allows for a fixed cane to be added as needs change provides a useful combination of bed safety with bed mobility * Fits twin to king size beds * Simple installation * Slide the Assista RailTM between the box spring and mattress secure to bed frame with mandatory safety strap Saturation Sound Pressure Level (SSPL) 113dB Frequency Range 200 5000Hz Total Harmonic Wave Distortion ≤3% Reference Test Gain 27±5dB Input noise ≤32dB Sound amplification 29±5dB Max Protects ROHO cushions from rough wear and tear fluids and the degenerating effects of poor quality ozone * Helps protect the cushion from rugged use and every day wear and tear * Protects against incontinence with its fluid resistant material and durable construction * Although this new cover is ruggedly designed it still allows for the benefit of the therapeutic skin protection of the ROHO cushion * Allows for easy access to ROHO cushion valves and the ISOFLO Memory Control© on SELECT Series cushions with a double pull zipper *