The European H4 headlight design is a much better light than the stock sealed beam units that came with the truck, or even the
newer design US Specification sealed beam lights. The European H4 design is basically a two piece unit that has a burner (bulb)
that is available in a variety of wattages and voltages that is placed into the back of a lens and reflector unit where it is
held in place with a spring clip. The benefits of this design is that you only have to change the bulb when one burns out instead
of the whole unit, and the lenses have a much more efficient design than those found in sealed beam lights. The European H4
lenses also are noted for having a different pattern than that which is found on the sealed beams found in the US. The change
in lens pattern is such that in low beam the light is kept down on the road in front of the vehicle and to the right side (to
illuminate the shoulder). The low beam pattern thus looks somewhat like this __/ In high beam, the light is directed
primarily down the road in front of the vehicle. One nice benefit of this lens to other traffic, especially for someone
approaching a truck that has its lights as high as the M37, is that the low beams don't blind the other drivers as much as a
“regular” sealed beam does.