Reduces the risk of possible injury or damage due to accidental air line disconnect. Uses double click to engage properly. First click locks coupler and plug; second click engages air pressure. When disconnecting, first click will relieve air pressure; second click allows coupler and plug to be safely disengaged. Coupler Size (in.): 1/4, Male or Female: F, Swivels: No, Style: M, Pieces (qty.): 1