Features:*Precise transmission: Made of effective aluminium alloy with oxidation treatment, our GT2 timing belt pulleys provide high transmission accuracy and forestall slippage throughout .*Frictionless transmission: With exact enamel spacing and excessive transmission efficiency, our timing belt pulleys present smooth transmission and save energy.*Easy installation: Our timing belt pulleys have an easy structure and are smooth to install, assemble and disassemble.* and finely crafted: Our timing belt pulleys are fabricated from nice aluminium alloy and provide high durability and advantageous workmanship.*Versatile application: Our timing belt pulleys are extensively utilized in milling machines, tools mills, drilling machines, rolling machines or different machine transmission.Specifications:Colour: silverMaterial: aluminium alloyNumber of teeth: 20&80Transmission ratio: 1:4Installation aperture: Φ8mm/Φ10mmBelt length: 250mmBelt width:6mmPackage Included:2*Synchronous Wheel 1*Belt2*WrenchNote:1. The genuine colour of the thing could also be barely diverse from the pictures proven on web page brought on by many points similar to brightness of your computer screen and lightweight brightness.2. Please allow slight manual measurement deviation for the data.