The 6519-31 Sawzall® Recipe Saw Delivers Best In Class Cut Speed, Durability and Power With 0-3, 000 Strokes Per Minute, A 1-1/8 In. Stroke Length and A 12 Amp Motor. The Gear Protecting Clutch Extends Gear and Motor Life By Absorbing High Impact Forces and A Quik-Lok® Blade Clamp Offers Fast Tool-Free Blade Changes. to Provide Greater User Comfort, A Counter Weighted Mechanism Reduces Vibration For Smoother Operation and A Redesigned Front Grip Area Provides Best In Class Ergonomics.