Abstract: A quick connection coupler for securement to a complementary nipple is produced principally of plastic parts by using molded slide-type cam jaws in a molded tubular body for gripping the nipple, and by using a molded downstream seal retainer telescoped into the coupler body for supporting a downstream packing that is to effect a seal with the downstream end of the nipple. The seal retainer preferably provides a valve thereon that operates automatically to close and prevent back flow through the coupler when the coupler is separated from the nipple, and to be opened for flow therepast upon connection of the coupler to the nipple.