Coccyx Cushion Foam 18 x16 x4 w/Gray Vinyl Cover Gray (Vinyl) * 18 W x 16 D x 4 * Custom sizes available * Optional solid seat inserts available ($8.75 Upcharge) * Relieves pressure at the sacral area while offering patientÊs comfort and even distribution of weight throughout the cushion * Medium density fire-retardant foam is covered in either a poly/cotton in your choice of black navy or gray medical grade vinyl