Dual Edge Finder combines the two most common sizes (.500" and .200") into one tool. Use it on your mill to accurately locate working edges, shoulders, grooves, center points and scribed lines on a work piece. They are invaluable time savers and also an intelligent precautionary measure against damaging expense machinery. Dual diameter .200" and .500", accurate to .0005" 1 lbs (0.5Kg) shipping weight.