RV Designer Coupler Lock Pin With Chain 5/16in x 2 1/2" 5/16in x 2-1/2in. These coupler lock pins are constructed with zinc plated steel to protect from rust and corrosion. Each package contains one coupler lock pin with a chain. Features of RV Designer Coupler Lock Pin With Chain 5/16in x 2 1/2" Features a security chain that can be fastened to all couplers to prevent it from getting lost Constructed with zinc plated steel Resists rust and corrosion Dimensions: 5/16" x 2-1/2" Each package contains one coupler lock pin with a chain Package Contents: RV Designer Coupler Lock Pin With Chain 5/16in x 2 1/2" RV Designer H421: Coupler Lock Pin With Chain 5/16in x 2 1/2" 5/16in x 2-1/2in