A machined billet inline fuel filter built around a 61mm diameter body and fitted with a 75 micron element. The coarse 75 micron rating is deliberately chosen for the suction side of the system, ahead of the pump, where the job is to catch tank debris, rust and swarf without choking pump inlet flow. Run this in series with a finer post-pump filter to protect injectors and regulators properly. The billet housing unscrews for service so the element can be washed out and reused rather than replaced each time, which suits a car that sees regular track use. Check the port sizes on your housing before plumbing and support the filter in a bracket rather than letting it hang on the hoses.