Water Resistant & UV Resistant The window seal is made of 190T dacron and PU coating fabric, water resistant and UV resistant. Also with YKK dual anti-skid zippers and premium hook and loop tape, more considerate design for your good user experience. No More Insects Tired of disgusting flies and mosquitos? The window seal also can keep flies, mosquitos and other unwanted insects outside! No Damage to Window The window seal is pasted around your open window to zip around your hose and block the return flow of warm air. You don't need to drill a hole on window for exhaust hose anymore.