Also known as I-line fittings, these fittings have a male adapter that interlocks with a female adapter for more support than standard quick-clamp fittings.

For use in high-vacuum systems, these fittings use a metal reinforced O-ring to create an airtight seal. Also known as KF, QF, and NW fittings, they’re used for high-vacuum applications such as vacuum coating and heat treating, leak testing, and analyzing gases.