This cover will keep the bottom of your a/c unit clear of debris buildup, leaves, pine needles, etc. ........ When leaves or debris decay they give off acidic gases that eat at your a/c unit"s copper tubing, by making small holes that allow freon to escape, causing your compressor to fail........ Our covers extend the life of your unit all year round (even when a/c is in use) and they prevent rusting parts by moisture being trapped inside like solid plastic or vinyl covers (same as a trash bag). ........ Trapped moisture is the main cause of failure to electronics, electrical connections, switches and metal parts. ........ All our covers are durable and made of tough, synthetic fabric, pvc-coated polyester 100% breathable 1/4 inch mesh, and will last up to 10 years. We offer a "Full 5 year manufacturer"s warranty"........ A free maintenance kit comes with each purchase, containing suggestions, maintenance instructions and directions for quick and easy installation, there are no tools needed........."New Replacement" Four nylon long lasting bungee cords are included. ..... Proudly made by a Vietnam Vet. in America.