A 50mm billet fuel filter in methanol specification with AN10 porting. Methanol attacks seals and internal coatings that handle petrol without complaint, so an alcohol-rated filter uses materials selected to survive that exposure rather than swelling and breaking down over a season. The AN10 ports are appropriate given how much more fuel volume an alcohol engine consumes compared with a petrol motor of the same output; a smaller port would become the restriction in the system. The 50mm body keeps the installed package short for tight mounting positions. If you are converting a car to methanol, replace the petrol-specification filter rather than hoping it will cope, as the debris from a failing filter ends up in the pump.