Including one 3-position base plate with M-type connectors, one Oxygen/Moisture/Hydrocarbon filter for Carrier gas, two Hydrocarbon/Moisture filters for H2 and Air The FID Filter kit is the perfect all-in-one solution for purifying flame ionization detector (FID) fuel gases together with the carrier gas. This kit removes hydrocarbons, moisture and oxygen from the carrier gas and removes both moisture and hydrocarbons from the Hydrogen and Air fuel gases.