1.material:BI-metal HSS 2.size:19mm-76mm 3.with Hex shank adapter and extension shaft 4.packing:injection case ◊Hole saw:19,20,22,25,29,32,35,38,44,51,57,67,76mm◊3/8" Hex shank adapter with HSS pilot drill for 14-30mm hole saw◊7/16" Hex shank adapter with HSS pilot drill for 32-210mm hole saw◊1 PC 12" extension shaft 16 PCS Bi metal hole saw set