In a world full of electronic, battery operated gadgets, it can sometimes be refreshing to go back to basics and essentials, while still taking advantage of modern advancements. This caliper does exactly that. This caliper is made of stainless steel. This one is rigid and accurate, It measures in both inches and millimeters, also comes with a carry pouch. Measures inside and outside diameters plus depth. This caliper is a quality tool that will last a lifetime.