Caliper.Brass Sliding Gauge Pocket Caliper 3 1/4" Inch & 80mm makes precision measuring easy in either inches or millimeters even without battery power. 2. Bright caliper gauge in solid brass manual gauge includes thumb knob for easy length adjustment offers a combination of inches and millimeters. Product Description 1.The best choice for these high quality product. 2.Brass Color Size Measurement 80mm / 3 inches 3.Material Brass Brass Sliding Gauge Pocket Caliper 3 1/4" Inch & 80MM Jewelry Tool Gauge. This made gauge in solid brass offers a combination of inches and millimeters. Brass combination inch and millimeter gauges. Capacity 3" (80 mm).