5 Pack, 12", 14TPI, Straight Back Bi-Metal Reciprocating Blade, Metal Cutting Blade, Patented Tooth Design Utilizes Sharper Tooth Geometry For Faster Cut Rates, Aggressive Shank Angle Increases Tooth Contact, Maintaining Cutting Speed As Blade Wears For Longer Blade Life, Specially Formulated Anti-Stick Coating Minimizes Friction & Gumming.