An air filter housing (12) includes twist and lock structure (46) having a first position (FIGS. 5, 6) permitting axial movement (120) of a cover (44) and base (38) relative to each other, and being rotatable in a first direction (48) from the first position (FIG. 6) to the second position (FIG. 7), and in the second position (FIG. 7) preventing axial movement of the base (38) and cover (44) relative to each other, and being rotatable in a second opposite direction (78) from the second position (FIG. 7) to the first position (FIG. 6). Anti-rotation lock structure (80) provides a rotational retention force holding the twist and lock structure (46) in the second position (FIG. 7).