INSIZE Digital Wall Thickness Caliper 12" This Electronic Caliper is perfect for measuring the wall thickness of curved products like helmets, domes, and curved posts. The Long Upper Jaws, 6.181" in length, also help measure your products when a lip or ledge might prevent the measurement from being taken with a standard pair of calipers. Features include... 0-12" / 0-300mm Measuring Range 0.0005" / 0.01mm Resolution 6.181" Upper Jaws Length +0.0020" Accuracy SPC Output capable Stainless Steel construction Includes Fitted Plastic Case