Built using premium Challenge 3.9oz. Dacron, FX Club Optimist sails are the perfect solution for Club fleets and training sails. Built to the same quality standards as FX big boat sails, the Club Opti is the right sail for club racing, sailing schools and individual training sails. Standard features include: - Visibility Window - Premium fiberglass battens - Class Insignia - Telltales - Sausage bag