420D Waterproof Material: Turbine vent cover, are made of high quality 420D waterproof oxford cloth, with a silver inner layer, better waterproof effect, washable and durable. Suit for Most Turbine Ventilator: Roof ventilator cover has two sizes, the small size is: 12D x 17.5W inch(30D x 44W cm), large size is: 20D x 20W inch(50D x 50W cm) suit for most of roof cover. Bottom Straps Design:Outside units Air conditioner protection covers has a adjustable straps in the bottom, make the cover not easy being falling due to wind, easy to put on and take off. Dustproof and Waterproof: Black roof ventilator cover could protect the central ac unit from sun, dust, water, snow protection in winter, protect your turbine ventilator and keep indoor warm in winter. Specification: Material: 420D waterproof oxford cloth Size: S: 12D x 17.5W inch(30D x 44W cm), L: 20D x 20W inch(50D x 50W cm) Color: Black Warm Tips 1,Please make this product stay away from fire, , flammable and danger things. 2,Please choose our product according to your roof ventilator size. 3,In order to a long time use, we suggest clean it regularly.