Model AP-15TUC is a double re-entrant loudspeakers which delivers 15-watts of continuous power handling, superior intelligibility and unparalleled efficiency. The AP-15 Series operates within a nominal frequency response range of 400-14, 000 Hz and offers a sensitivity of 120dB at rated power to provide clear voice and signal communication. The trademarked squared-bell design signifies Atlas Sound quality and reliability. The Omni-PurposeÂ® mounting bracket (supplied on all models) achieves precise positioning in the vertical and horizontal planes with a single adjustment and includes provisions for loudspeaker installation on conventional surfaces as well as for strapmounting on I-beams or pillars. A built-in, 5 mfd capacitor is provided for line supervision. All models meet or exceed the UL Listed standards for audible signal appliances, standard 1480-Speakers for Fire Protective Signaling Systems and California State Fire Marshal (Title 19).AP Series loudspeakers are U.S. made to assure superior service reliability. Weather-resistant construction is metal and matching ABS plastic with metal components finished in grey epoxy.