smoke 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)

smoke grenade (smoke canister)

air filter

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

air defense filter center

engine filter

filter cap

filter center

filter head

filter plugging test

filter room

filter shell