Features: These Excellent Electronic Optical Edge Finder Quickly Locate Work Edges and Save Time When Finding Positions on Milling Machines, jig Borers, Etc. Pro-be Hardened Precision Ground, Not Necessary to Rotate While Measuring;The Sensor is Spring Load-ed to Prevent Accidental Damage by Overun. LED Lights Instantly and It Beeps When Pro-be Touches Conductive Work Piece, Louder and Brighter. Shank Diameter: 20MM, Pro-be Diameter: 10MM, Accuracy: 0.005MM. Suitable for traditional milling machines and integrated processing machines. Package Includes: 1x Electronic Edge Finder 1x Wooden Box Specifications: Material: Stainless Steel Box Size: 200x60x35mm 7.87x2.36x1.37 in Finder Length: 160mm 6.3 in Shank Diameter: 20mm 0.8 in Pro-be Diamter: 10mm 0.4 in note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.