【Measure before you buy】For example, the external dimensions of 17 inches wide and 20.5 inches high fit most return systems up to 14 inches wide (given the thickness of the return valve, it is best to leave at least 3 inches for a better fit). Freeze Protection】The extra layer of insulated aluminum greatly improves freeze protection, preventing your piping system from freezing or bursting even in cold winters, saving you from costly repairs. 【Durable Quality】Made of aluminum foil, PP cotton and waterproof 600D oxford cloth, with good insulation and waterproof performance. Easily adapt to harsh conditions such as sun, snow and rain, providing all-weather protection for your valves. [Firmness] The widened Velcro closure ensures a strong bond to keep your housing tight. Even in strong winds, you don't have to worry about it blowing away. 【Functional and practical】 2pcs 304 stainless steel cable ring, designed for locking device, can make your housing anti-theft. Product parameters: 62*63cm:Package size: 32*32*5cm, weight: 400g (PE bag)