Rat Guards. Prevent rats and mice from climbing aboard your boat or into your house. Spring-loaded shields easily attach on boat mooring lines or home overhead utility lines. Made In the USA Made of Durable Plastic with Patented Spring Door for easy installation Stainless Steel components for use in salt water environment. Used by the US Navy, the US Coast Guard and NOAA vessels. Made in U.S.A. Made in U.S.A. Available in sizes, 10, 15 and 17 inch.