this was the most popular model, followed by the junior. the 2 large "projector" style parabolic bulbs gave quite a snapping flash. lots of contractor, city works vehicles used these, they were the heavy duty light that could stand up to anything. they came in 2 or 4 bulb models, in red, green, amber, blue and clear. these were most recognized on the ontario provincial police cruisers back in the 70s, 80s and up to mid 90s. with a low current draw of 5 amps, these could almost be used as portables on cigarette plugs! i pulled my 2 off a old towtruck for 40$ I WILL BUY ANY DA LIGHTS D.O.A.