This is a Single Axle Galvanized Boat Trailer Fender for use on trailer wheels that measure 12 inches in diameter or less. This fender is 16 Gauge Galvanized Steel. Galvanized Coated fenders are excellent for use in the marine environment. Having a Galvanized Coating on your fender will significantly reduce corrosion and rust caused by saltwater. This 16 Gauge Galvanized Boat Trailer Fender is also very sturdy, ideal for protecting your boat from road debris.