UPD : Air Fittings : Pneumatic Couplers and Plugs – Plugs – 1/4″ Male Thread

DIAMOND-U
Plated steel couplers have hardened steel balls and stainless steel springs. Coupler plugs are heat treated and plated to
reduce wear on critical mating surfaces. Amflo’s Diamond-U Series of couplers are identified by three narrow grooves
on the coupler sleeve, and the short tapered tip of the plug. They interchange with Diamond-U as well as units produced
by other manufacturers.

WARNING: Couplers and Plugs on this page are intended for use on compressed air lines only. All have a maximum
rated working pressure of 300 PSI.