1For High Accuracy Machining: Three kinds of sleeves with different inner diameters, simple structure, easy to use, often used for high accuracy machining 2Wear Resistant Bearing Steel: Bearing steel material with high frequency quenching treatment, wear resistant and durable, and does not require frequent maintenance 3Not Easily Deform or Crack: The bushing will not deform, age or crack as easily as traditional plastic bushings 4Balance and Reduce Vibration: Suitable for a 1in wide bench grinding wheel. Equipped with a bushing can balance the grinding wheel, reduce vibration during rotation, have a low friction coefficient and no noise 53 Different Sizes: Contain different size of ID 1/2in x OD 5/8in, ID 5/8in x OD 3/4in, and ID 3/4in x OD 1in, 2pcs each Item Type: Reducing Bushing Adapters Material: Bearing steel Color: Silver Quantity: 6Pcs Specification(inner diameter x outer diameter x length):1/2in x 5/8in x 1in(2pcs) 5/8in x 3/4in x 1in(2pcs) 3/4in x 1in x 1in(2pcs) Purpose: Grinding wheel 6 x Reducing Bushing Adapters