The seal, as an unused spare part, was manufactured by the Parker Seal company, and is still in its original packaging. Supplied with the seal is a blanking gasket bearing the Rocketdyne logo, this gasket is the distinctive red colour that can be seen on many images of F1 and J2 engines that are fitted with protective shrouds and covers. The seal is identified with a part number, and can be seen in the parts manual, a page of which is shown below. The four-way valve operation is described in the engine start sequence as being used to divert hydraulic pressure from the Ground Supply Equipment, this pressure being used to open the main Liquid Oxygen Valves