DEWALT BLACK&GOLD HSS Drill Bits have a speed tip and a tough core for increased durability. The bits also incorporate a no-spin shank that eliminates the frustration of the bit spinning in the chuck. Supplied in a TOUGH CASE+, this is part of a connectable case system which is TSTAK™ compatible. Individual TOUGH CASES can be clipped together for easy transportation. This 10 Piece Set contains the following sizes: 3, 3.5, 4, 4.5, 5(x2), 6(x2) 8 and 10mm. Ref: UTTK5543