Trimax Stainless Steel Coupler Lock 3 1/2in.Span. The O-ring seal and water tight cap help seal out dirt. Easy 1/4 turn locks and unlocks head. Full length pin is constructed of solid forged stainless machined steel. Includes coupler lock and two round keys. Features of Trimax SXTC3 Stainless Steel Coupler Lock 3 1/2in.Span Fits couplers with up to a 3-1/2" span Full length pin is constructed of solid forged stainless machined steel Internal O-ring and watertight cap seal out moisture Easy 1/4 turn locks and unlocks head The round key wont bend or break like flat keys and are impossible to pick Package Contents: Trimax SXTC3 Stainless Steel Coupler Lock 3 1/2in.Span Trimax SXTC3: Stainless Steel Coupler Lock 3 1/2in.Span