An AN8 shut off valve for inline mounting in a fluid circuit. Stepping up from AN6 to AN8 matters where flow is the priority, typically high-output fuel systems, oil cooler circuits and engines running alcohol fuels that demand far greater volume than petrol. Putting a valve in the line means a filter change, pump swap or plumbing modification no longer starts with draining the tank. On a race car it doubles as a manual isolator for a circuit you may want to shut down between sessions. Position it so the handle can be reached and operated without removing bodywork, and so the valve body is supported rather than hanging on the hose alone.