The third and last of the generally accepted pool cleaner technologies, the pressure-side cleaner, was invented by Melvyn L. Henkin of Tarzana, California in 1972. His "Automatic Swimming Pool Cleaner, United States Patent Number 3,822,754 utilized three wheels to allow the machine "to travel underwater along a random path on the pool vessel surface for dislodging debris therefrom". The design is probably familiar to pool owners as the Polaris Pool Cleaner.