Fits 12 in. turbines with external support structures. Fits 14 in. turbines with internal support structure. Polyester fabric with double stitched seams, strong draw rope and heavy-duty brass grommets. The water resistant Polyurethane coating prevents water from entering cooler while still allowing water vapor to escape, inhibiting moisture buildup inside cooler. Cover is suitable to all seasons as it protects cooler from rain, snow and UV.