The fittings are also known as an instrumentation fittings. They have two sleeves (double ferrules) that bite into metal tubing for a strong seal.

Also known as an instrumentation fittings, the Yor-Lok fitting has two sleeves (double ferrules) that bite into metal tubing for a strong seal. The tube stem fitting is a short length of tubing that inserts into the end of another tube fitting.

Also know as pump connectors, hose is sized to specific lengths for attaching to pumps.