The ultimate in versatility the universal countersink changes diameter to whichever drill bit it is attached. Simply unscrew the two hex head securing bolts and place over the drill bit you want and it instantly adjusts to accommodate the size of drill. The tungsten carbide cutting edges cut cleanly. Suitable for use with 3.0mm to 7.2mm drill bits, the universal countersink can also recess the hole if required by plunging the bit further into the material. Drill bits not supplied.