Finally, a simple bolt on coupling device for boosted Arcitc Cats and Yamaha SR Vipers. Simple effective and priced right. Simply turn the blocks to a new position to go from no coupling (Stock) to the available 3 positions. Our moto for this item (Keep It Simple Stupid) gives you the option of having some or no coupling with a simple adjustment. All parts and hardware included for installation. This product will NOT fit sleds with track lengths shorter than 153".