Trotter Manufacturing Inc. is considered one of the largest U.S. producers of hydraulic valve spools to off-highway equipment OEMs. The spools control the restriction and flow of high-pressure oil in hydraulic cylinder valves used tractor and construction equipment lines. Skip Trotter, President, likens his products to the processors in a computer: “Our spools are the brains of the valve and these products constitute 90% of our shipments.”