IP54 waterproof stainless steel: IP54 level strong waterproof, to solve the problem of ordinary digital calipers contact with water on the bad; fine polished stainless steel, so you digital calipers more hard, more durable than ordinary digital calipers Huge clear display screen: The display screen is larger than ordinary digital calipers, allowing you to easily see clear numbers. The thumb rolling and locking screw provide easy sliding, accurate positioning, and fine adjustment INCH/MM Conversion: One button can quickly convert two measuring unit ( INCH / MM ). Measuring Range: 0 - 150mm ( 6 in ) / Resolution: 0.01mm ( 0.0005 in ) / Accuracy: ± 0.02 mm ( 0.001 in ) Multifunctional Use: The digital micrometer can easily and accurately measure internal, external, height and depth dimensions. Automatically shut off: When you have no action on the dial caliper, it can automatically shut off after 4 minutes.