Softer, smoother and faster. Grippers™ are formulated with performance urethane for effortless high-speed cruising. Featuring BUFF Core Technology which helps absorb impact, reduce de-hubbing and create a smoother ride. All PROTO wheels are manufactured with bearing removal slots for quick and easy replacement. All PROTO wheels are pre-installed with PROTO Murders bearings. Limited 90-day warranty against chunking and de-hubbing. Made in California!