Breathable Optimist top cover made of Moistureguard 2000, a heavy duty 900D polyester with a polyurethane membrane which has excellent breathability & is fairly water-resistant. The Optimist cover can be tented by storing the spars under the cover inside the boat. Wide skirts around the edge of the hull for good protection. Fast & easy to install with two straps with 2 adjustable quick-clip buckles.