The construction of this cushion assists in the reduction of pressure to the user's vulnerable bodily points and areas, whilst providing stability and shock absorbtion - A three layer combination of visco elastic memory foam and high density polyurethane foam make this seating appliance extremely durable and effective - Will help with the reduction and prevention of pressure sores and ulcers - Memory foam ensures muscles are relaxed and tension relieved - Supplied with Harley Premium Dartex waterproof / VP cover - Other cover options available. Suitable for patients up to hgh risk (with appropriate nursing care).