gas-particular filter unit (GPFU)

particular device

filter housing / filter unit

filter unit / filter housing

band-pass filter / bandpass filter (BPF)

dust filter / dust shield, particle filter

dust shield / dust filter, particle filter

particle filter / dust shield, dust filter

finite impulse response filter (FIR-filter)

passband filter; bandpass filter (BPF)

filter unit

gas gun; (tear) gas launcher

gas generator unit

gas turbine engine inlet unit

gas turbine engine turbine unit

battery coolant unit / battery-coolant unit (BCU)

gear reduction unit / gear-reduction unit

position and navigation unit / position navigation unit (PNU)

pinch (a unit) out of a large unit

air filter

filter-separator

fuel filter

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