Sends audio page to, and is powered by the 5540MP-24Y6. UL and cUL Listed. Input is received from a microphone input or audio pair signal source such as phone PBX. Indoor, Type 2 enclosure when flush wall mounted. Indoor, Type 12 or 2 when mounted to outdoor listed 4" square utility box. Outdoor, Type 3R and Indoor Type 12 or 2 when mounted with 5542WPK to outdoor listed 4" square utility box.