Sail27's premium Mainsheet - 7mm FSE Robline's Dinghy Sheet specially developed for use as a main sheets on racing dinghies. A tightly woven polyester cover takes all the load and the polypropylene core is held fast, preventing twists and knots. The polyester/polypropylene combination make the line light and minimizes water absorption. The polyester cover protects the polypropylene core from UV. Everything you want in a dinghy sheet, all in one. FSE Robline's Dinghy Sheet was designed specifically to prevent the dreaded twisting and kinking that can keep you from easing the sheet at critical moments.