Hi Temp Bumper Plate Material: Crumb rubber Insert: Fitted Stainless Steel Insert Diameter: 2 inches Bumper Plate Diamter: 17.5 inches Color: Black High Bounce Bumper Plates are built from a resilient recycled vulcanized rubber and featuring a 2" stainless steel insert. These plates feature a crumb design. Withstanding repeated drops with minimal noise and exceptional durability. Bouncy rubber plates allow you to drop a fully loaded barbell without damaging your equipment or floor. Low Noise Bumpers are far quieter when they’re dropped on the floor than the other types of plates, because they’re wrapped in rubber. They’re also usually used with rubber matting, which helps to deaden sound and protect the floor at the same time. Floor Protection The thicker width of bumper plates coupled with the flat surfaces on the plates helps to protect your floor. By spreading the weight across a larger surface area there’s less pressure through one particular spot when the weights are dropped.