Features: 1Anti?falling component design properly solves the problem that the sleeve is not fixed and easy to fall off when disassembling force. With it, novices can easily disassemble the bottom bracket. The spring acts as a buffer when the sleeve is screwed out of the bottom bracket to avoid wear. 2One?piece structure, accurate and standard 20?tooth design, no burrs, smooth hand feeling, perfectly fits the bicycle bottom bracket key. Precision and high compatibility, the square hole/spline bottom shaft is suitable for 20 keyways (16 keyways downward compatible). 3Made of high?quality carbon steel, after electrophoresis process, anti?oxidation, with strong toughness and strength, square hole/spline bottom bracket can be used, easy to lock and force, suitable for 8mm / 0.3in hole bottom shaft. 4Enlarge the occlusal area and stabilize the tooth profile the sleeve teeth of the bottom bracket are tightly fitted with the keyway of the bottom bracket, and the force is uniform and continuous teeth without damaging the keyway. 5The contact area of most sockets and wrenches on the market is too small and easy to slip. The upgraded version of the socket has an occlusal contact surface of 18mm / 0.7in, which has even force and is labor?saving. 6High-carbon tool steel, thickened curved teeth, not easy to damage, beneficial to protect the bottom bracket it needs to be used with a 24mm spanner or a 1/2-inch bristle spanner. Package included: 1 x Anti-Dropping Component 1 x&nbspBottom&nbspBracket&nbspSleeve