Provides smooth operation and long service life. Standardization size, used for machine tools, electronic equipment, pump industry, airships, reducers, machinery plastic, motors, textile machinery. With the characteristic of high stability, high reliability. It is a rubber sealed ball bearing, with a good dustproof effect. This ball bearing is mainly made of high quality bearing steel and steel material, durable with wear resistance and collision resistance. Product Description Specifications: Model: MR115-2RS Material: Bearing Steel, Steel, Rubber < p>Color: blue Inner diameter: 5mm/0.20in Outer diameter: 11mm/0.43in Thickness: 4mm /0.16in Weight: 39g Package Included: 25 x Rubber Sealed Ball Bearings