Cover boot Knot-a-boot 6 mil are clear polyethylene, over-the-shoe boot covers designed for quick, sanitary entry into barns, poultry houses, kennels, and clinics. The easy slip-on design can be worn with or without the handy tie feature for a secure fit. Intended for single use, these disposable boot covers help prevent unwanted contamination from one facility to another. Standard size and 6 mil thickness offer dependable coverage in livestock and poultry environments.