AeroCell II Pressure Relieving Wheelchair Cushions, High Cell are still the ideal solution for patients at risk of developing pressure sores , now, they are even more durable for longer protection against skin breakdown via inflatable air cells. The High Cell (4"H) version is for those at the highest risk for skin injury.Choose between single-valve or dual-valve options. Single-valve cushion inflates in one step. The dual-valve permits each side of the cushion to be inflated to a different degree of firmness for a custom fit. Includes a free Bulb Inflator. Flame and urine resistant. Cushion is comes with a black stretch nylon washable cover with slip-resistant bottom. Cushion constructed of environmentally friendly polyurethane.