Variable Area Rotameter - 150mm 316 Stainless Steel Flow Meter with Precision Valve, Maximum Flow Range: Air - 19 std. ml/min (0.04 scfh) | Water - 0.19 ml/min (0.003 gph), Float Material: Glass, End Fittings: 1/8" FNPT, Frame Seals: Viton-A, Tube Seals: Viton-A, Valve Option: High Precision Valve