The General Tools Plastic Dial Calipers offer precision measurements at affordable prices, making them a great choice for hobbyists and do-it-yourselfers. This thousandths-reading caliper features a no-glare dial for accurate readings of inside, outside, depth and step measurements. The slide is easily advanced and retracted with a free-wheeling thumb roller, and the 6” bar scale is marked with 1/10” and 1mm graduations for guaranteed accuracy.