Century's Impact Pro™ Black Oxide Drill bits are made from premium M2 steel to withstand heat and wear under rigorous drilling applications. Single piece fully ground construction lasts 6X longer than two piece constructed drill bits. No center punch needed: Century 135° quick cut points are self-centering and penetrate faster with less pressure. Will not walk or wander at the starting surface. 1/4" quick change shank fits all quick change adapters and cordless impact tools. 24 piece multi-purpose set. Set includes: (1) magnetic bit holder, (1) #1, (2) #2 and (1) #3 Phillips, (1) T-10 and (2) T-25 Star-Drive, (1) #6-8, (1) #8-10, (1) #10-12 Slotted, (1) #1, (2) #2, (1) #3 Square insert bits, and power bits in (1) #2 Phillips, (1) #Square, (1) 1/4", (1) 5/16" nutsetters and (2) 1/8", (1) 5/32", (1) 3/16" and (1) 1/4" Impact Pro drill bits.