The Federal Signal Model AM50 is a compact, two watt, transformer coupled speaker for use in emergency notification or paging applications. The unique design of this 4 in square speaker centers around the short, folded, re-entrant horn that is interposed between the diaphragm and the surrounding space. This speaker is supplied with wiring terminals and strain relief for inbound and outbound speaker wiring. The AM50 is designed primarily for wall mounting and includes a trim ring for adapting to any standard 4 in square or weatherproof back box. This speaker is Underwriters Laboratories Listed for ''Fire Protective Signaling Use'' and California State Fire Marshall approved.