The BKF is an industrial filter for protection against acid gases and vapors, organic vapors, hydrogen cyanide, and arsenide.. Some BKF filters also include a particulate filter, which is indicated by a white stripe down the filter.
The BFK is an olive-drab coloured canister and appears to be constructed similarly to the EO-18. The outside markings contain the name, year and month of production.
The filter weighs approximately 760 grams.