Accuracy 0.005MM;Quickly locate work edges;Probe Hardened & 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;These excellent tools quickly locate work edges and save time when finding positions on milling machines, jig borers etc etc;They employ a highly sensitive location sensor and utilize a red pilot light which can be clearly seen and an audible beeper The location of the end surface, outside & inside circle diameters can be detected;Shank Diameter: about 20mmItem length: about 160mmBall Diameter: about 10mmBattery: 2 x LR1/1.5V/N Alkaline Battery (Size N/LR1/1.5v) (Not included)Color: silverMaterial: steelPackage Included:1* Electronic edge finder with original boxOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.