SPI Deluxe Dial Indicator AGD 1: Dial Diameter 1.65" Features Include... Measuring Range: 5 mm Reading: 0-50 Revolution Graduation: 0.01 mm Face Counter: Yes Color: White Accuracy Meets or exceeds Federal Specifications. Easy reading graduations Thread Size: 2.5mm Stem Diameter: 8mm Dial Diameter: 1.65" Adjustable bezel for convenient zero setting with clamp screw. Lug back supplied except where noted. Certificate of calibration