Stable and : using high-quality materials, stable connection, safe and , small and appearance, Lightweight and portable: the design is small and light, does not occupy too much, It has a lot of space and is easy to put in daily backpacks, suitcases, etc. It is suitable for travel and business trips. The product has superior performance, is easy to carry and simple to install. specification Product name: 1:3 reduction drive pulley colour:Silver Material:aluminum Size:200 x 8 x 8mm Package Contents: 1 x Reduction drive pulley Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.