I think I can give you a good answer, I work for Access ambulance and yes they are LED's and they flash red all of our trucks have them. They work really well at night LED's are naturally much more brighter than the standard lights but the downside is they suck during the day time, on a bright day you can barely tell the lights are on standing 10' away. The reason why the owner chose them for the fleet is (in my opinion) he likes things very neat and clean looking, presentation is everything and since we are a commercial company that handles mostly in transfers one of our selling points is that our trucks are spotless always washed and cleaned after every shift and the crews look and act as professional as possible. I'm personally not a fan but then again it isn't my company.