Our cockpit cover installs over the boom in front of the mast to the end of boom with a heavy duty marine zipper at the mast. MC, X and J Boat covers have boom pocket. Grommets with tie down rope secure the cover to the deck. Fabric is gray vinyl coated polyester, water repellent, UV and mildew resistant. Pricing is $65 additional for Sunbrella Acrylic. Please contact us for Sunbrella Acrylic option and color selection.