The active earmuffs are designed to protect the wearer from harmful loud noise. They are attached with a connector to the Spirocom mask unit to transmit sound from the group communication and PTT sound from the long-distance radio.

The earmuffs are equipped with electronics for reproducing ambient sound. Two externally mounted microphones capture the ambient sound and speakers inside the earmuff reproduce the sound in stereo. The sound reproduction is limited to a maximum of 82 dB(A) to prevent hearing damage.

The earmuffs are connected to a variant of Spirocom intended for earmuffs and have brackets that fit the Fire Helmet F300.