Complete kit includes hardware and tensioners for Rolux reel mowers This minimizes maintenance and ensure the correct tensions. Fits all Rolux X17, X20, X25, S17 and S20 mowers Replaces original chain tensioner Durable materials built to last Installs in 20-30 minutes using hand tools Add to cart when checking out with a new mower purchase to have the kit installed before your new mower ships The Rolux Automatic Chain Tensioner Kit includes all you need to set and forget your mower's chains. This retrofit kit takes up all available slack in the drive chain and cutter chain, allowing complete adjustment of the reel without having to relieve tension on the chains. Watch Installation Instructions Here Note: All S20 and S17 9-blade mowers sold 2026 or newer have this kit installed from the factory.