|The visual signaling beacon shall be Tomar model 824 or approved equal. The light source shall be a plug-in field replaceable xenon strobe lamp. The beacon shall have a field selectable double or quad flash rate of 68 to 72 double flashes per minute, or 58 to 62 quad flashes per minute. The warning beacon shall have a Lexan® lens and universal mount base. The DC voltage units are to have polarity protection, and must have built-in RFI filters to protect against radio interference and spike voltages. All beacons must have fully potted power supply and base. The AC units shall be designed to withstand multiple line transient spikes of 6000V without damage. Light intensity is to be 1020 effective candelas in double-flash mode, and 1200 effective candelas in quad-flash mode. Voltage ranges shall be 12-28VDC, 120 VAC, and 240VAC. Strobe light shall be designed to accept a dome guard and mounting bracket.