The Robomow Automatic Lawnmower is a battery-powered robotic lawnmower that mows a lawn on its own. It mows an area that lies within a pegged-down perimeter wire (much like an electronic dog fence). The mower 'recognizes' the wire using a sensor that ensures it stays inside the designated area. It will reportedly back away from any obstacle it encounters, mulches the cut grass downward (not 'side-chute' it), and shuts the blade off when picked up or tilted. The Robomower runs off a rechargeable battery, and does not pollute the air. It performs best on lawns with relatively few obstructions and terrain irregularities. Four models are available, depending on size of lawn.