Matrix II bi-metal teeth for greater durability., The 1 -Inch tall blade body reduces blade twisting for straighter, more accurate cuts., Can cut into walls that contain wood, nails, plaster and aluminum, FANG TIP . Ordinary tips bounce or skate on the work piece. FANG TIP bites into the wood on first contact., A thicker, more rigid blade body resists fracturing and bending for maximum durability., Includes: 9 -inch 5 teeth per inch AX nail embedded wood cutting SAWZALL reciprocating saw blades (5-pack)