Their special feature is that they have a check valve incorporated in both the male and female parts, thus preventing fluid from escaping when the quick coupling is disengaged. The fitting is valved with a free passage quick coupling. The main features of the product are: it is made of AISI 316, the threading is standard BSPP (others on request), the seals can be standard VITON®, or at the customer's request, with PTFE anti-extrusion. The burst pressure is 2.5 times the normal operating pressure, and the connection is made by means of a ring nut retraction.