ADJUSTABLE ELSTIC HEM ROPE: Considerate design adjustable elstic hem rope on the cover bottom that can adjust the cover tightness avoid the cover blow away. WATERPROOF & DUST-PROOF & ANTI-UV: Made of Oxford Cloth material,it has the function of Waterproof when rainning and Dust-proof & Anti-UV on sunny matter what kinds of weather, it can prevent the sun wind and rain,keep the clean clean.