This is the ultimate lock for use in marine or other outdoor environments where salt air and rugged environments are present. This is a 37Mm padlock, and is 100% solid stainless steel, including body, shackle, and inner parts like the cylinder and springs. This product is ideal for all types of boat docks, use on piers or anywhere the salt air corrodes traditional steel locks. Our line of corrosion resistant stainless steel locks are designed to perform in even the most harsh environments.