ITEM NAME:20mm Save Time Digital Electric Edge Finder Stainless Steel Milling Quick Locate Features: Quickly locate work edges. Probe hardened and precise 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. They employ a highly sensitive location sensor and utilize a red light which can be clearly seen and an audible beeper. The location of the end surface, outside and inside circle diameters can be detected. &;nbsp; Item type: Electronic edge finder Material: Stainless Steel Color: Silver Size: Shank Diameter: about 20mm Shank Length: about 160mm Ball Diameter: about 10mm Battery: 2 x 1.5v(size:N) alkaline battery (not included) &;nbsp; Package Includes 1 x Electronic edge finder Notes:&;nbsp;&;nbsp; 1.Differences due to light and display, the color of the item may be slightly different images. 2.Please allow 1-2cm differs due to manual measurement..Item type: Electronic edge finder. 1 x Electronic edge finder. Quickly locate work edges. Material: Stainless Steel. There is a safety spring puller which puts. The ball precisely back to the position when ball breaks away from ball seat.