Thrashin Supply Derby Cover For Harley Big Twin By proudly displaying the Thrashin Supply Co. derby cover, you send a clear message about your values and appreciation for American ingenuity. Embrace the boldness and authenticity this cover brings to your bike, adding an extra touch of pride to your riding experience. Features: Machined in house at Thrashin's Chatsworth, California machine shop Billet 6061 Aluminum Hard black anodized or hand polished and put back in the machine for twice cut Comes with gasket