In early 2000 several companies developed robotic "vacuum" cleaners. Some examples are Roomba, Robomaxx, Trilobite and FloorBot. Although most do not create a vacuum for cleaning, these machines propel themselves in patterns across a floor, cleaning surface dust and debris into their dustbin. They usually can navigate around furniture and find their recharging stations. Most robotic "vacuum" cleaners are designed for home use, although there are more capable models for operation in offices, hotels, hospitals, etc. By the end of 2003 about 570,000 units were sold worldwide.