Features： 1、CNC strengthened treatment has no abnormal noise, and the locking shaft is press‑fitted. The interlocking design can reduce noise and improve rigidity. The sealing system is easy to maintain and lubricate. 2、Washers are used for 22‑24mm / 0.87‑0.94in hollow cranks to adjust the distance of the chain center line of the crank disc; three fine‑tuning washers (1mm/2mm/3mm) are provided for the convenience of customers. 3、Because it is non‑magnetic and does not absorb dust, it can reduce bearing peeling and noise in advance, high strength, light weight, 1/3 of the weight of metal, good surface smoothness, and low friction coefficient. 4、Exquisite threaded lock enhances the lateral stability without loosening and no abnormal noise. Conversion of the reducing sleeve can be used with cranksets of different brands and models. 5、Integral sealed bearing, which prolongs the service life, retains the lubricant in the bearing, has good dustproof and waterproof effect, and is suitable for harsh riding environments. 6、Ceramic bearing bearing, silicon nitride ceramic ball, corrosion-resistant, wear-resistant, long service life, and can be used as usual in harsh environments. 7、Using T6 heat‑treated high‑strength aluminum alloy material, CNC process processing, the weight is light and the strength will not decrease. Specification： Item Type: Bike Lock Bottom Bracket Material: Aluminum Alloy + Ceramic Bearing Package List： 1 x Lock Bottom Bracket 1 x Reducing Sleeve 3 x Washer