Red and green indicators to separate zones for increased visibility of pressure management. Pressure Range: MPa: 0 - 0.4; Connection Size: R1/8; Transparent Cover Material: Polycarbonate; Connection Diameter: R1/8; Outer Diameter: 1.4 inches (37.5 mm); Model: Back Screw; Compatible Tube Outer Diameter: D (37.5 mm); Index Accuracy: %FS): ± 0.1 inches (37.5 mm); Lens Dimensions: Minimum Scale (mm) Total Height: Height (in.): Measuring Range (3 mm); Magnification (mm) Code Number: 10 3-4573