The Alert Model 40530A is a phase separation detecting and particulate removing filter with 30 micron cellulose media which is recommended For gasoline and alcohol blended fuels when a higher cleanliness level is required. The 40530A utilizes a standard 1 -12UNF mounting thread 3/4 flow required for most fuel dispensers. The 40530A is designed to detect phase separation in alchol-gasoline blended fuels with 15 % maximum alcohol and is compatible with unleaded gasoline and regular gasoline eliminating the need to change filters if you change fuels. It utilizes an epoxy coated interior shell to eliminate oxidation which can cause pin-hole leaks from the inside. PetroClear filters are not to be used with aviation fuels.