Size:41mm Material type:Alloy Steel Batteries included?:No Product Dimensions:1 x 1 x 1 cm; 20.06 Grams 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 Steel Color: Shown as picture Options: 41mm; 41.8mm; 47mm; 49mm; 52mm Size(Outer/Inner Diameter): Approx. 41/30mm; 41.8/30mm; 47/34.5mm; 49/38mm; 51/40mm; 52/41mm Weight: Approx. 21-32g Suitable 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 About this item [5 Sizes Optional]: Headset bearing outer/inner diameter 41/30mm; 41.8/30mm; 47/34.5mm; 49/38mm; 52/41mm [Waterproof & Dustproof]: The sealing ring is good for keeping dust and water away to lengthen the durability [Stable Performance]: Built-in grease in the slot can prevent the balls from corrosion and make them rotate freely [Exquisite Workmanship]: Fine workmanship ensures sleek surface and smooth rotation; The bike headset bearing help makes your riding more enjoyable [Premium Material]: The bike stem bearing is made of premium bearing steel; Anti-rust, sturdy, durable & longlasting [5 Sizes Optional]: Headset bearing outer/inner diameter 41/30mm; 41.8/30mm; 47/34.5mm; 49/38mm; 52/41mm [Waterproof & Dustproof]: The sealing ring is good for keeping dust and water away to lengthen the durability [Stable Performance]: Built-in grease in the slot can prevent the balls from corrosion and make them rotate freely [Exquisite Workmanship]: Fine workmanship ensures sleek surface and smooth rotation; The bike headset bearing help makes your riding more enjoyable [Premium Material]: The bike stem bearing is made of premium bearing steel; Anti-rust, sturdy, durable & longlasting