Through proven performance, patented VT/VTF Series have earned worldwide acclaim for service reliability. These cost-effective units offer compact size, functional flexibility, optimum intelligibility, effective sound distribution, and high-level output. All models contain a high efficiency compression driver with maximum acoustic conversion efficiency. (A quality which reduces number of units needed to attain specified sound pressure levels and provides substantial savings in amplification-power requirements and labor costs.) Die-cast, water-sealed construction withstands vandalism, vermin, moisture, corrosion, and vibration during indoor or outdoor use. Selection includes a basic 8-ohm version and 70.7 or 25-volt transformer models with DC blocking capacitor (C) where noted. Features All Models Produce High Level Output, Optimum Intelligibility, and Effective Dispersion Choose from Surface or Recessed Models in Red or Neutral Gray Finish Durable, Die-Cast, Water-Sealed Housings Withstand Vandalism, Vermin, Moisture, Corrosion, and Vibration Easy and Low Cost Installation Via Standard E.O. Boxes Ideal for Reliable Voice/Tone Signaling in Public Area Emergency Communications and Heavy-Duty Industrial Applications Model Produces High Level Output, Optimum Intelligibility, and Effective Dispersion UL Certified, Safety Listed to UL1480 Patented Emergency Loudspeakers Available in 8-Ohm, 70.7V, and 25V Versions Surface Models in Neutral Gray Finish Units Meet or Exceed UL Standard 1480 for Fire Protective Signaling Systems when Used with Compatible Control Equipment Units Meets UL Standard 1480 for Fire Protective Signaling Systems when Used with Compatible Control Equipment