Smooth Idler Pulley Kit

From the shop's description

Idler pulley is used on the other part of belt drive system (timing pulley and timing belt) to transmit the rotation of the main pulley to other parts of your system. It also can be used for belt tension adjustment and for better transmission Efficiency. The Smooth Idler Pulley Kit is an easy to assemble idler free wheel that can be used with Timing Belt up to 9mm wide! This idler pulley can be mounted in a variety of fashions to fit your design. It can be plate mounted as well as direct T-Slot mounted using a T-nut The Kit Includes: (1) Smooth Idler Pulley – Delrin (1) 5mm Shim 2) Ball Bearings – 625 2RS (5mm Bore) (1) 1/8" Nylon Spacer (1) M5 * 25mm Low Profile Screw (1) Lock Nut with Nylon Insert