Adjustable Countersink Carbide Tipped. One Countersink fits all drill diameters from 1/8″ (3.0mm) to 9/32″ (7.2mm). Perfect grip of the two Cutting Teeth over the drill by means of screws, allowing easy setting of drilling and countersink depth in ONE PASS. Two Carbide Tipped Cutting Teeth for clean cuts and longer tool life. Each countersink supplied with its Key in an attractive blister pack with sliding card. Recommended drills for ultimate performance use DIMAR’s Machine Drills 205-D, Metric or Inch sizes.