Heavy duty Class 2 welded link chains for trailers up to 3500 lbs. Zinc plated finish to resist rust, with heavy steel hook and safety clip that latches to keep chains attached to tow vehicle. Chain size 5/0, mount with 7/16 inch bolts. Meets SAE and V-5 standards. Two 36-inch chains per package. NOTE: Do not mount chains to trailer tongue with the same bolts used to mount coupler. Cross safety chains under coupling, allowing only enough slack for turns.