Black * 18 W X 16 D X 4 * Custom Sizes Available * Optional Solid Seat Inserts Available ($8.75 Up-charge) * Relieves Pressure At The Sacral Area While Offering Patients 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