Slot Strip is a specially formulated laminate of Polyester film and Dacron sailcloth.It has very special characteristics of rigidity, flexibility and tear resistance making it a perfect film to cover your centreboard/daggerboard slot to keep water out but allow your centreboard/daggerboard to pass through it.Slot Strip can also be used as transom flaps on Racing Dinghies and Rudder/keel fairings on Yachts.