This fitting is a push in fitting so you just push the line in from both sides. It is mainly used where a stronger connection is required on a rigid port.
One side is a standard 8mm (5/16) duotight push in fitting, where the other side is a compression adapted duotight (Screw Lock) for 1/4" / 6.35mm rigid fittings.
These high quality acetal fittings are made with EPDM o-rings that are reliable, will not perish like cheaper rubber. The acetal plastic is also chemical and UV resistant so it will last for a long time even in testing conditions.
