AX21320

the AX21320 filter fits with

AX21311

the AX21311 filter fits with Rig Master Auxilliary Power Units

AX21310

the AX21310 filter fits with Case, J.C. Bamford, Kobelco, Link-Belt, Volvo Excavators

AX21309

the AX21309 filter fits with GENERAL MOTORS CORP.

AX21287

the AX21287 filter fits with Caterpillar Equipment

AX21251

the AX21251 filter fits with Cummins QSB6.7 (Tier 4 Interim & Final), QSL9 (Tier 4 Interim & Final), QSX11.9, QSX15 (Interim Tier 4) Engines