8.5″ wide. Biker Gel. Used in combination with 506604 solo seat. Note: Biker Gel has a unique way of forming to the rider/passenger, distributing weight evenly across the seat and removing pressure points. Due to its memory characteristic, Biker Gel never loses its shape. It will not freeze, crack, melt or break down and it will never leak because it is a solid gel, not a fluid. Don’t expect a soft, pillowy feel. Biker Gel provides a firm, supportive foundation that shows its true quality better the longer you ride.