Duralastics Conical Step Drill Bit - 1/4 in to 1-3/8 inDrill your own trays with ease with a self centering conical step drill bit! Drills holes from 1/4 in up to 1-3/8 in. Step measurement marks are etched directly on the drill bit. Titanium coated for durability and reduced friction. Drill up to 10 different sized holes with one bit!