Zoom Certified • Low profile, requires only 3.3" (84 mm) mounting depth • High speech intelligibility coupled with full-range music reproduction • Thin-edge, magnetically attached grille • Tap switch allows for 70V/100V or 16Ω low impedance operation • Tuned bass reflex port for optimized low frequency performance • Loudspeaker overload protection for 24/7 failsafe operation • ETL listed to conform with UL Std 1480A and UL 2043; Certified to CSA C22.2#62368-1