I purchased a set of these Milton Quick 1/4" Quick Couplers for my 3/8" air hose as well as the 1/4" Milton Male Plugs for my air tools.  The quality of this coupler will beat anything else on the market by far.  Very easy to operate and NO AIR LEAKS!  Order a set of these for your air tool set-up.  You will be extremely pleased with the high quality and ease of operation of these products.  This is yet another top quality, made in the USA product from Milton.