Front Sliders Aluminum nut and backing plate available in anodized colors Integrated track stand grooves machined into the slider spools Stainless steel solid rod with stainless nut will nut rust like all thread of lesser designs Replaceable spools are machined from UHMW-PE for its excellent low drag and high wear compared to Delrin of lesser brands Rear sliders Integrated rear axle adjuster blocks make these a clean install and a solid mount for the slider spools Blocks are laser etched with chain alignment marks for easy alignment. Blocks are available in anodized colors Replaceable Spools are machined from UHMW-PE for its excellent low drag and high wear compared to Delrin of lesser brands and mounted to the blocks with stainless hardware