Evotech Performance has developed an innovated spindle/bobbin system which allows the bobbin head to rotate on impact. This is down to the aluminum spacer system that provides a solid core for the location of the nylon bobbin head. Using this system we have increased the overall durability and impact resistance of our bobbin kits. The spindle sliders/bobbins are retained by roll threaded stainless steel spindles for increased strength. The spindle slider/bobbin kits comprise of two nylon bobbins, two anodized aluminum spacers, stainless steel spindle, nuts and washers. Made from high performance engineering materials in order to protect your expensive fork bottoms and brake calipers in the event of a spill. Fits "Desert Sled" Years 2017 to 2021. Fits "1100 Models" Years 2018 to 2021.