Simple in-line device shows gas or liquid flow. Indicates maximum flow of 95 ml/second down to 5 ml/second. Brightly-colored paddle spins freely when flow occurs and is made visible through clear polystyrene outer case. Should not be used with corrosive fluids or fluids over 65°C (150°F). Serrated tubulations accept 1/4"" to 3/8"" I.D. tubing (6-9 mm). Dimensions: 3.5 x 2.125 x 0.75"".