This is Roomba, the robotic vacuum that autonomously navigates through multiple rooms to clean hard floors and carpets. Two virtual wall lighthouses project infrared beams that confine the vacuum to one room until it has cleaned the entire surface and then allow it to pass to an adjacent room. Sensors redirect the unit when it encounters furniture, walls, or stairs, and its anti-tangle technology reverses the rotation of the brushes when it encounters rug fringe. The unit's specially designed dual, counter-rotating agitator brushes spread carpet fibers and enable the vacuum to remove hair and other detritus from low- and high-pile carpets. Roomba can be scheduled to navigate autonomously through your home up to seven times per week or the remote control allows you to send the vacuum on an impromptu spot cleaning-a feature unique to the Hammacher Schlemmer model. It cleans up to four rooms per charge and automatically returns to its drive-on charger when its battery runs low. Includes one replacement filter and two replacement brushes. Remote control requires two AA batteries and lighthouses require two C batteries. 2 1/2" H x 13" Diam. (11 3/4 lbs.)