EPIC 3-Spoke ultra light aluminum wheels feature a custom made billet 6061-T6 aircraft grade aluminum hub that is machine lathed for perfect balance. The highly resilient solid urethane tread will not go flat and is designed to minimize energy loss and absorb vibration. Arched tread design ensures the contact surface is spherical to improve pivot bility. The extra width better distributes downward pressure allowing the wheel to maintain higher flotation and does not sink into carpet,gravel, etc. Designed for those who want the ultimate smooth ride.