Oxide treatment resists corrosion, helps prevent bit from rusting. 135 degree split point tip starts on contact, cuts with less force. Reduces shank above 3/8 allows the use or larger drill bits in a 3/8 chuck. Rubber overmolded case protects kit if dropped. Tap and die selection chart for convenience reference Automatic indexing for easy bit access and identification. Removable cartridges: easy to carry bits from case to worksite. Contains the following drill bit sizes: 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 11/64, 3/16, 13/64, 7/32, 151/6, 1/4, 17/64, 9/32, 19/64, 5/16, 21/64, 11/32, 23/64, 3/8, 25/64, 13/32, 27/64, 7/16, 29/64, 15/32, 31/64, 1/2.