I picked up this blue strobe beacon at a surplus store today. It is made by North American Signal. It has a self contained strobe power supply and is a single flash pattern. It has a rubber base. The label on top of the dome shows how the light should be oriented when mounting it. I wondered why it would matter until I removed the dome and saw it has a horizontally mounted linear type strobe bulb. As I looked closely at the square plastic tray all the electronics were sealed into, I noticed the tray had a latch and hinges like the small plastic containers with clear lids. Obviously the lid was removed. The tray is mounted to a round metal plate with sits inside the rubber base with two bolts extending out the bottom for mounting. This was the first round strobe beacon I have seen with a linear type strobe bulb.