The AM30 AudioMaster is a Series of Siren Like Speakers by Federal Signal Possibly Released around the 2000s..
On FedSig.com It Says:
"The Federal Signal AM30 is an 8 Ohm constant directivity, re-entrant speaker that is ideal for most public address or paging applications. The constant directivity horn design provides excellent sound coverage throughout the typical frequency range of speech. The AM30 is molded from impact-resistant, beige acrylic-styrene-acrylonitrile (ASA). The unique omni-directional swivel mount of this speaker allows the unit to be pointed anywhere within a 360° half-sphere of area"