Product Material Waterproof Spa Cover is made of 170G top polyethylene material,Five-layer thermal insulation spa cover can reflect heat,lock heat,resist UV,Engery-saving and Eco-friendly,saving your electricity bill all year round. Powerful Functions Hot tub cover can protect your Hot Tub from Dirt, Hot Sun,Dust, Snowstorm,Rainstorm,High Wind,Hail, Bird Droppings etc all year round. Product Size Outdoor cover is 83 Dx28 H,it fits most round 81 inch inflatable hot tubs,please do not choose the same size as your hottub,because the same size will be difficult to install and remove. Install Door Design Hook and Loop Closure makes customer very easy to install it and make the cap tighten,the install door design for external heaters or pump,which saves your time without disassemble the outdoor unit. Wind Belt Design Two stainless steel D-lockers are very easy to be loosed or tighten,it won't break.Allows adjustment for a tight in a harsh environment to prevent blow off.