Description Fleetguard FF5488 is a spin-on diesel fuel filter with cellulose media, providing 5 micron filtration at 98.7% efficiency (SAE J1985) to protect fuel pumps and injectors in heavy-duty applications. It suits Cummins ISC, ISL, QSB, QSC and QSL engines and replaces Cummins 3959612, with common cross references including Baldwin BF7815, Donaldson P550774, NAPA 3697 and WIX 33697. The filter uses a 7/8-14 UNF-2B thread, has an overall height of about 175.77 mm and a largest outside diameter of about 93.47 mm, with a standpipe-free design for straightforward replacement in compatible fuel filter heads. (ccifilters.com)