Description:Size:41mm Material type:Alloy Steel Batteries included?:No Size Name: 41mm Promotions can vary depending on size name. About this item ANTI-RUST & DURABLE: The bike stem bearing is made of quality steel material, which is anti-rust, sturdy and durable to use for a long time. FINE WORKMANSHIP: Fine machining ensures sleek surface and smooth rotation, bicycle bearings fits perfectly with your bike headset. ANTI-DUST & WATERPROOF: The sealing ring bearing is good for keeping dust and water away, prevent impurities from entering to lengthen the durability. ANTI-CORROSION: Built-in grease in the slot can prevent the balls from corrosion and make them rotate freely. GREAT ACCESSORIES: The bicycle bearings provide rigid support for the handlebars, it's an useful accessory for replacing old headset of bike. ANTI-RUST & DURABLE: The bike stem bearing is made of quality steel material, which is anti-rust, sturdy and durable to use for a long time. FINE WORKMANSHIP: Fine machining ensures sleek surface and smooth rotation, bicycle bearings fits perfectly with your bike headset. ANTI-DUST & WATERPROOF: The sealing ring bearing is good for keeping dust and water away, prevent impurities from entering to lengthen the durability. ANTI-CORROSION: Built-in grease in the slot can prevent the balls from corrosion and make them rotate freely. GREAT ACCESSORIES: The bicycle bearings provide rigid support for the handlebars, it's an useful accessory for replacing old headset of bike.