The VIP-130AL-M-SA, Intrado Revolution, IP High-Efficiency Horn and Network Interface is the perfect choice for high-quality voice paging, emergency alerts and loud ringing for large indoor and outdoor areas. VIP-130AL-SA includes a mounting base for quick and easy installation on multiple surfaces (electrical boxes, beams, walls, poles etc.). The VIP-130AL-M-SA Horn can be use in indoor or outdoor applications. The VIP-130AL-M-SA Network Interface is to be used indoors.