Precision and hardend Titanium coating wear-resisting non-magnetic and the inside structure also has special material, it is non-magnetic Shank: 10mm (shank diameter tolerance H7 ) suitable speed: 400--600rpm Probe: 4mm and 10mm Biggest diameter of edge finder: 20mm Colour: gold Material: high-speed steel Package Contents: 1 x edge finder PLEASE NOTICE--This edge finder is special, the biggest diameter is 20mm, it is bigger than the normal ones, so the edge finder is more steady and high precision. Only the above package content, other products are not included. Note: Light reflection 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.