Robotic lawnmowers are nothing new, but nearly all of them require digging up the perimeter of the lawn and installing wire to let the mower know where not to cut. Segway's Navimow uses precise positioning technology instead, making setup considerably faster. Like other mowers, it charges itself when the battery runs low and is IPX6 rated for water resistance. It also has an adjustable cutting length, quietly operates at 54 dB, and has a host of built-in safety and anti-theft features. Available in four models, which step up in both cutting range and price.