Spyder's saw blades for reciprocating saw are designed for cut applications in thin and thick metals as well as in nail imbedded wood. The blades compatible with Irwin models are ideal for tough cutting tasks that require an aggressive, durable, and longer life blade. Shatter and heat-resistant, the 8% cobalt bi-metal blades power through the toughest cuts. They offer up to 10x more cuts and 3x faster than conventional bi-metal blades. The kit includes: (5x) 9-inch blades 6 teeth/in.