1、Sturdy: Bike bottom bracket is made of carbon steel spindle, stainless steel bearings, strong, long service life, sealed bearing components to provide better sealing and lubrication performance. 2、Protect Bike Frame: Integrated bike bottom bracket can protect frame, more power output, it's better than ordinary structure bottom bracket. The weight is very light and does not impose an extra burden on the bike. 3、Save Effort: The bike bottom bracket has fine workmanship, accuracy threads can be better connected, 2 bearings structure makes the spindle more flexible and less labor intensive. 4、20 Slot Axis Cover: Made with pure steel, CNC machine cut for a one piece finish, fits tightly without shaking. The L (left) R (right) markers are clear, with arrow indicating the tightening direction. 5、Safe and Easy to Install: The bike bottom bracket no abnormal noise, prevent assembly stuck, safe to use. Double bearing thread design for better connection. Helps you install quickly and easily without adjustment. Item Type: Bike Bottom Bracket Material: Carbon Steel Spindle, Stainless Steel Bearings 1 x Bike Bottom Bracket 2 x Screw