The Clenzoil Field & Range Patch Kit is the ultimate One-Step-Solution for cleaning, lubricating, and protecting fine firearms.Get the same great Clenzoil Field & Range product that you have used for years on 50 cal/12 guage pre-saturated, cotton-fiber patches! The Clenzoil Field & Range Patch Kit is the ultimate One-Step-Solution for cleaning, lubricating, and protecting fine firearms. It is especially great for cleaning and rust-proofing the bore of muzzle loaders, rifles, and shotguns.