air filter

band-pass filter / bandpass filter (BPF)

dust filter / dust shield, particle filter

dust shield / dust filter, particle filter

filter housing / filter unit

filter unit / filter housing

particle filter / dust shield, dust filter

finite impulse response filter (FIR-filter)

passband filter; bandpass filter (BPF)

air defense filter center

air intake filter

aerial refueling / air refueling / in-flight refueling (IFR) / air-to-air refueling (AAR)

air combat capable helicopter / air-to-air capable helicopter

air support field pack, field pack air support, airborne / para (air support) / Pathfinder Bergen

filter-separator

fuel filter

gas-particular filter unit (GPFU)

home-made face filter

individual portable filter

oil filter

RF interference filter

filter stack

military-grade filter

slave oil filter

bag filter

bath filter

centrifugal oil filter

disk filter

engine filter

filter cap

filter center

filter head

filter plugging test