Rogers KNW Series Powered by Kobelco is designed and constructed to exacting quality standards resulting in long operating lives, minimum maintenance and low operating costs.  The KNW series is designed, manufactured, assembled and tested in the United States and provides completely oil-free air. The KNW series offers high efficiency rotors, dual vent seals with stainless steel rings, and lubrication of gears and bearings to increase gear and bearing life, ensure purity, and improve efficiency.