$These are the best quick couplings on the market. High-quality metal. These couplings are designed to handle 1,000's of connections and disconnections. So you will have no leaking air. Made in the USA. We have these in stock and ready to ship. ---1/4" Lincoln Plugs ---1/4" Male NPT Thread --- Solid Steel ---Heavy-Duty ---Air: -40 to +225F ---300 psi ---Made-in-the-USA ---10pcs.