This purchase is for a set of frame sliders for the above bike model. The sliders feature the new design of anodized aircraft grade aluminum inserts to prolong the puck life. The spacers are machined from 6061-T6 aircraft grade aluminum. The spacer is bolted to the engine mount and the slider puck is screwed onto it. Since this spacer is made of solid billet aluminum there is no need for re-tightening the engine bolt in the long run where you have to do so with plastic slider as the plastic would gradually give in and therefore making the bolt loose. The puck material are made of UHMW-PE (ultra high molecular weight polyethylene), a tough plastic with good strength, wear resistance and dimensional stability. It is more dimensionally stable than Nylon and used in many industrial ball bearing and friction reducing applications. Compared to Delrin, it is softer but tougher. Delrin is harder but more brittle. It is an ideal material for slider since it can absorb more impact force onto itself and therefore reduce the impact on the frame and engine. The slider pucks can be inexpensively replaced in case of a low-side. We use highest grade commercially available 12.9(177,000 psi in tensile strength) wherever possible. Rest assured that you are getting the best material commercially available.