Milwaukee 49-22-4175 General Purpose Ice Hardened Hole Saw Kit, 15-Piece None Made in USA The product is manufactured in United States ICE HARDENED for up to 50% longer life than the competition Matrix II Bi-Metal Teeth for greater durability ICE HARDENED for up to 50% longer life than the competition Matrix II Bi-Metal Teeth for greater durability Positive Rake Angle for fast cutting Radiused Tooth Back reduces stress on teeth Deeper Gullets for fast chip removal and Funtional Slot Geometry provides easy plug removal