New Puritest 6" Caliper Digital electronic 3-In-1 Way Jewelry gauge Measure Metal Stones Measuring range: 0-150 mm/ 0-6 in. Resolution: 0.01mm/ 0.0005 in Repeatability: 0.01mm/ 0.0005 in. Maximum measurement speed: 1m/s Power: 1 x 1.5V SR44 (silver oxide cell) battery (included) Battery life: 1 year for continuous usage / 3 years under normal operation Size: 250mm x 50mm x 6mm