Most popular coupler latching mechanism ever designed. Made in USA. Hooks up quickly and easily to tow vehicle. Heavy-duty safety latch designed to prevent accidental uncoupling. Padlock hole provided for trailer security. Factory adjusted to ball size. Serviceable ball clamp assembly for field replacement. Zinc finish. Meet or exceeds SAE standard J684. (GVW: gross vehicle weight). Rating is maximum for trailer capacity. NOTE: FUW 22300S0173 has sharkskin finish-environmentally friendly, self healing. Maximum corrosion resistance.