Enter the 40V System with the RYOBI 40V HP Brushless 20” Self-Propelled Lawn Mower. With 40V HP technology, it delivers more power than a 150cc gas mower, making it a true gas replacement. Ideal for up to 1/2 acre, this mower comes with an included 40V 6Ah lithium battery for up to 42 minutes of runtime. 40V HP technology combines a brushless motor, advanced electronics, and lithium batteries that automatically react to mowing conditions by increasing the blade speed to eliminate bogging down and power through the toughest cut. Plus, its variable speed self-propelled drive system helps you finish the job quickly and effortlessly. Best of all, it is part of the RYOBI 40V system where any 40V battery works with any 40V product. This self-propelled mower is backed by the RYOBI 5-Year Manufacturer's Tool Warranty, 3-Year Manufacturer’s Battery Warranty, and includes the RY401018 40V HP Brushless 20" Self-Propelled Mower, OP40605 40V 6Ah Lithium Battery, OP408 40V Fast Charger, Grass Catcher Bag, Start Key, Mulch Plug, Side Discharge Chute, and Operator's Manuals.