Hole Dozer General Purpose Bi-Metal Hole Saw Set (21-Piece)The MILWAUKEE 21 Piece HOLE DOZER Bi Metal Hole Saw Kit features RIP GUARD, the strongest tooth form in the industry and is backed by a Limited Lifetime Tooth Break Warranty (an industry first). Theyve built the hole saw blade teeth with more steel behind the cutting edge for added strength. This added tooth strength combined with 8% cobalt, gives added life to the teeth, providing users with increased productivity on the jobsite, as well as