Features Easy to disassemble and assemble: easy to disassemble and assemble, including synchronous wheel with 20+60 teeth and 2 synchronous straps. Maximum durability: aluminium alloy material with surface oxidation treatment to ensure maximum durability. WIDELY USED IN MECHANICAL TRANSFERS: Widely used in mechanical gear such as milling machines, gear forming machines, drills, hob machines, etc. Replace old or broken ones: the timing belt pulley made of aluminium alloy is good to replace the old or broken ones and directly renovate. Reliable and durable: the synchronous wheel is easy to install and disassemble, reliable and durable in use, very practical. Specification: Item Type:Synchronous Wheel Material: aluminium alloy. Colour: silver. Number of large teeth: 60 Number of small teeth: 20. Inner hole: approx. 5 mm. Screw: M4 x 4 mm. Belt with closed bow: width: approx. 6 mm / 0.24 inches, length: approx. 200 mm / 7.87 inches. Package list: 2 x large synchronisation wheel. 2 x small synchronisation wheel. 2 x belt with closed loop. 4 x M4x4 screws. 1 x wrench. Package List 2 x Big Synchronization Wheel 2 x Small Synchronization Wheel 2 x Closed Loop Belt 4 x M4x4 Screw 1 x Wrench