This purchase is for a pair of frame sliders for the above bike model. The sliders feature a new design of a complete solid puck without a hollowed-out center. This increases the strength and contact surface to about 30%. 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 a plastic slider as the plastic would gradually give in and therefore making the bolt loose. The front part of the kit features the under fairing frame slider which like it is stated sits behind the faring. It protects the fairing bracket and other critical engine components. The puck material is 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. The bolts are made of grade 6 stainless steel. 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