Briggs Stratton 44T877 0001-G1 vertical Commercial Series engine is 724cc and puts out 24.0 HP (maximum horsepower). This engine has a 1″ x 3-5/32″ crankshaft with a 1/4″ keyway and comes equipped with a 12V electric starter, 16A alternator, cyclonic air filter and oil cooler. A muffler is not included, but options are available for purchase on our site. This model replaces 44Q977-0037-G5. Briggs Stratton Commercial Series engines are made to get the job done in extreme conditions thanks to features like a 5-Step Debris Management System, cyclonic air filter and super-finished crank pin. Specifically designed for zero-turn mowers and other high-debris applications. Buyer protection package provides two-year limited consumer engine warranty. 50-State CARB Compliant. All engines purchased from us ship for free and are foam packed for added protection during transit.