The Worx Nitro self-propelled lawn mower features rear-wheel drive with variable speed control - one lever changes the pace of the mower depending on your preference or how thick the grass is. Auto-Intellicut technology uses internal sensors to adjust the torque to either power through thicker grass or back down to conserve battery power. The brushless motor and Power Share PRO batteries provide gas-like performance and runtime without the hassle, mess and cost of maintaining a gas engine.