Millipore has a broad selection of fittings, adapters, valves, gauges, and tubing that can be used in conjunction with Millipore filtration systems. With stated exceptions, material of construction is Series 300 stainless steel.Tri-Clamp (TC) fittings are referred to by convention as 1 1/2", 2", etc. 1 1/2" TC fittings connect to 1" or 1 1/2" O.D. tube sizes. 2" TC fittings connect to 2" O.D. tube size only.