ATLAS SOUND VT-27UCN Voice/Tone Surface Mount Compression Driver Speaker with 15-Watt 70V Transformer - Gray Description From the Manufacturer: 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. All models terminate via barrier strips. VT Series models are surface-mount units; VTF Series are flush-mount units for recessed installation. VT Series mounts standard 4" E.O. Boxes; VTF Series mount 4" or 4 11/16" SQ backboxes and require model AR or MR adapter rings respectively (order separately) Optional mounting accessories are offered including: indoor and outdoor enclosures, a bi-directional housing, adapter plates and rings. Suffix model with color: Red (R) or Neutral Gray (N). Ex: VT-157UCS. FEATURES: All Models Produce High Level Output, Optimum Intelligibility, and Effective Dispersion 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 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 We are selling a huge amount of new alarm equipment! Please take a look at our other listings! Feel free to message me for an inventory list including other items that we haven't listed yet! *WE CAN WORK OUT A DEAL FOR BULK ORDERS* SHELF: B