XM FITNESS 45lbs Crumb Rubber Bumper Plate SKU: 5146Crumb Rubber has the ideal durometer rating to absorb bounce and shock, preventing damage to your olympic lifting bar. Crumb Rubber technology dissipates the impact giving you 10,000 30,000 drops and reducing stress on the lifting bars. On the field tests have shown XM Crumb Rubber Bumpers bounce less than other high end rubber bumper plates on the market. Less bounce equals less shock and less noise. CERTIFIED VIRGIN RUBBER: Unlike some weight