OIL COOLERS are required in all steering systems with engine driven power steering pumps. Our standard coolers have 1" NPT water and 3/8" NPT female oil connections with a 2" x 9" tube bundle. Our high flow coolers have 2" NPT water and 1/2" NPT female oil connections with a 3" x 6" tube bundle. The tubes are made with cupro nickel.