THESE ARE A MILWAUKEE 6 PIECE HD FLAT BORING BIT KIT 49-22-0071 CONSISTING OF 3/8", 1/2", 5/8", 3/4", 7/8", AND 1" + ONE IRWIN 2-1/8" SCHLAGE BIT I WOULD ASSUME IS FOR BORING DOOR LOCK HOLES IN WOODEN DOORS BUT NOT SURE