Made of 100% 420D oxford with PVC coating,Enhanced dust-proof and waterproof effect.(420D could easily withstanding damaging weather elements which can last much longer than other seat cover made of 210T,210D,300D. ) Spring clasp can adjust tightness.Added a new buckle webbing to prevent wind blowing. Convenient storage, can be folded into pocket size. Double stitches and UV60+ to prevent tearing. Please measure the outside of your cockpit before your purchase,Move up to the next size if your measurement falls on maximum length and width. CAUTION:pls measure include(around the outside of the cockpit lip length and width)