Application: use with 10mm Shank boring bits to drill and countersink for screws in one pass.Drills sold separately. Left hand tools rotate counter-clockwise, #416005, (D) diameter: 16mm, (D) shank: 5mm, Overall Length (L): 16.5mm, rotation: left hand, 416005 carbide Tipped Countersink L/H 16mm DIA x 16.5mm Long x 5mm Shank