3N1 Cushion: Donut Ring, Coccyx Cushion, Seating Wedge. Innovative lobes improve seating balance over regular donut cushion design. Center oval cut-out provides relief for medical conditions and comfort for hemorrhoid and recent surgery. Large Coccyx cutout reduces tail bone pressure and provides comfort during prolonged sitting. Tapered front edge reduces pressure points underneath thighs and easily accommodates table, desk and driving positions. Dimensions: 17.5" wide x 13.5" deep. 215 lb