Diablo,15 Pack, 9'' x 14-18TPI, Metal Steel Demon Reciprocating Blades, Full Contact Arched Edge Design Specifically Designed For Maximum Performance In Metal Cutting Applications, Design With Ultra Hardened Cutting Edge Provides Faster Cuts In Fewer Passes Resulting In Less Heat Build Up To Deliver 5x Longer Cutting Performance Than Those Of Standard Blades, Dual Tooth Design Features A Double Tooth Configuration With Small Gullets For Faster Material Removal & Extra Durability.