A large-bodied billet fuel filter measuring 61mm across, chosen where a slim in-line filter would restrict flow. The greater body diameter gives more element surface area, which means lower pressure drop across the filter and longer intervals between cleaning on a system moving serious volume. That matters on high-output turbo builds and methanol or E85 setups, where flow demand is high and fuel can be harder on the system. As a billet housing it strips down for element cleaning rather than being replaced entire. Mount it where you can reach the housing for service, and observe the flow direction when plumbing it in.