Powered by a Briggs & Stratton 163cc 725EXi Series engine QPT� Technology - the ultimate in reduced noise and vibration technology, ReadyStart� - Starting made easy! No Prime, No Choke, Smooth Pull-Start, Quad Blade Cutting System - 4 swing-back blades deliver a cleaner cut & improved catching in thick, wet grass, Ultimate Mulching Performance - Unique mulching blade-disc design generates air-circulation beneath the mower continually cutting the grass - creating a fine mulch