Specification: new Shank Diameter: approx. 20mm Length: approx. 160mm Ball Diameter: approx. 10mm Battery: 2 x 1.5V (Size N) (not include) Accuracy: 0.005MM Feature: Use a highly sensitive location sensor and a red pilot light. Quickly locate work edges, save time when finding positions on milling machines, jig borers etc etc. Probe hardened and precision ground. Not necessary to rotate while measuring. LED lights instantly and it beeps when probe touches conductive work piece. There is a safety spring puller which puts the ball precisely back to the position when ball breaks away from ball seat. High strength and hardness. Durable in use. Package included: 1 x Electronic Edge Finder (Ship by random color) Note: Please allow 0-1cm errors due to manual measurement. Item color displayed in photos may be showing slightly different on your computer monitor since monitors are not calibrated same.