Milwaukee 49-22-4185 28-Piece All Purpose Professional Ice Hardened Hole Saw Kit The product is easy to use The product is durable 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 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