1The flower core rod has been hardened and heat treated with high hardness. 2The surface polishing process is not easy to deform after repeated beating and has a long service life. 3The surface of the sleeve has been sandblasted and nonslip. After molding, the surface is polished. 4With threedimensional sandblasting, the device will not slip, and the surface also presents a fine metallic texture. 5The thread is accurate, the connection is firm, and it is not easy to fall off. It is a great DIY bicycle replacement part.