Initially I ordered the competitor Dixon Quick Coupler along with Dixon Valve & Coupling DCP20B. Advertised as buy together, the Dixon quick coupler was much larger and the male Dixon fitting rattled inside it. However, the DCP20B fittings did fit a quick connect I previously was using. The Dixon quick couplers were returned an the Milton 715BK M was ordered. On receiving the Milton 715BK, It was tried immediately and they were a great fit with the Dixon Valve & Coupling DCP20B under pressure. Air tight!!!. Just be sure to use Mylar tape or thread sealer when attaching to the air hose--just as a precaution. I am mentioning fittings from a different manufacturer to assure buyers that Milton works with most male couplers.