The Challenge Fujin/Furai Return Idler Kit is a complete redesign of the the return chain path and you will not believe how simple and quiet it can be! With a fully floating design and all new mounts, there's no need for a return side chain tube. In addition to the floating chaintube and upgrading the power side idler, this kit changes the chainline to move the mid return idler down below the power side chain instead of beside it. This keeps the power side chain from touching the idler, and allows the idler to be full width and have full side plates. The Challenge Return Idler Kit will re-invent your ride, and you'll love it.