In 1915, a young Frank Donaldson, Sr.—then a Bull Tractor Company salesman—visited a customer whose tractor kept breaking down in his dusty field. Frank hand-fashioned a simple air cleaner to protect the engine and invented the world’s first effective air cleaner for a tractor engine. Employees continue to establish strong relationships using our advanced filtration technologies and service solutions to help protect critical equipment, improve performance, and keep essential operations running smoothly.