|Crouse-Hinds Type M Single Face Head|
The Type M signal first appeared in 1950s while the Type DT (art deco style) was still in production. The Type M provided those who wanted it a more modern looking signal and the DTs were out of production by 1959. The Type Ms were nicknamed "Bread Pans" due to their rounded, pan-like backs.
Reflectors were typically polished aluminum with latch wings. The sections did not have drains and it is not uncommon to see discolored streaks on the backs of the reflectors. Earlier signals used fabric covered wire. Type M signals have been seen with smiley, faint smiley and T3 (beaded but no smiley) lenses.