The 9400 Sport 4WD uses vortex vacuum technology that enables extraordinary cleaning power without losing suction. A rear water propulsion system enables the robot to blow debris off of stairs and out of tight corners. The 9400 Sport cleans all pool surface types and scrubs the floor, walls, and tile line by using a solid, non-pleated scrubbing brush. This machine has a filter canister that has 4 times the capacity of other similar cleaners. That means fewer filter cleanings (up to 70%), and lower operating costs (pennies per day). By engineering the machine with top access, the debris canister can be cleaned without turning it over and emptied with a simple shake and spray. This model features 2 cleaning cycles (1.5, 2.5 hrs.) The 9400 Sport cleans pools up to 50' in length and has an activ motion sensor to prevent tipping and cord tangling. Weighs 16 lbs. Heavy duty matching transport caddy is included. 2 year warranty.