15 piece, black oxide, drill bit set, oxide treatment resists corrosion, helps prevent bit from rusting, 135 degree split point tip starts on contact, cuts with less force, flatted shanks above 11/64" eliminates slippage in drill chuck, reduced shank above 3/8" allows the use of larger drill bits in a 3/8" chuck, case with rubberized grip & sliding latch, set includes: (2) 1/16", (2) 3/32", (1) 7/64", (2) 1/8", (1) 9/64", (1) 5/32", (1) 3/16", (1) 7/32", (1) 1/4", (1) 5/16" & (1) 3/8" drill bits.