Performance Machine Vision Derby Cover For Harley Touring Performance Machine Vision derby covers give you the ability to see what's going on inside the heart of your bikes clutch pack. The UV and abrasion resistant polycarbonate lens is framed by a 6061-T6 aluminum bezel to add structural integrity as well as provide an even distribution of clamping force to eliminate cracking. The covers is precision CNC machined out of billet aluminum and come complete with chrome hardware. Features Aluminum lens bezel eliminates cracking UV, abrasion, hazing and yellowing resistant polycarbonate lens CNC machined from billet aluminum Chrome hardware included