Here is what the 264 filter means to you...

Characteristics Sid Harvey/Mitco Mfg.
Model 264
General Filters
Model 1A-25A
Surface Area, in² 57 52
Volume, in³ 12 12
UL Rated Firing Rate, GPH 15 10
Clean Pressure Drop, in Hg 0.25 0.25
Dirt Capacity, oz 6 4
Ending Pressure Drop, in Hg 20 20
Filtration Depth High Medium
Number of Gear Teeth 17 16
UL Rated Working Pressure, PSI 50 12
UL Specified Replacement Element Yes Yes
UL Listed Gasket Material Yes Yes
Galvanized Can Yes No
Rust-Proof Top Yes No

* MICRO-FLOW® Cellulose Acetate (biodegradable plant fiber) filter element (white)
** Rayon filter element (white)