Posture Wave Cushion...The high resilient foam provides a comfortable upper surface with a central insert for posture support. Provides bony prominences protection at the base of the spine with integral safeguard foam inserts. The cushion has a removable cotton cover with a zip opening. Designed for use in a wheelchair and/or day care chairs, by patients in the low/medium risk category. Maximum User Weight: 12 Stone (75 kg).