Features:The bearing is made of quality steel material, anti-rust, sturdy and durable.Fine machining ensures sleek surface and smooth rotation, fits perfectly with your bike headset.The sealing ring is good for keeping dust and water away to lengthen the durability.Built-in grease in the slot can prevent the balls from corrosion and make them rotate freely.Useful accessory for replacing old headset of bike. Specification:Material: Bearing SteelColor: Shown as pictureOptions: 41mm; 41.8mm; 47mm; 49mm; 52mmSize(Outer/Inner Diameter): Approx. 41/30mm; 41.8/30mm; 47/34.5mm; 49/38mm; 51/40mm; 52/41mmWeight: Approx. 21-32gSuitable for Repair most of the full hidden, semi-hidden and external bearing headset on the market.Note: Unable to repair old loose ball or ball (like bearing) headset.Package List:1 x Bike Headset Bearing.