Willis Lamm's Traffic Signal Collection (And Street Lights Too) Clicking on a picture will bring up a larger view in a new window.   General Electric M-400 "Cobra Head" Street Light

In 1959 GE produced the M-400 which was a 400 watt mercury vapor luminaire that had an internal ballast. It was the original of what was to become GE's "cobra head" style of street lamps. The luminaire's shape attracted this nickname. There were many revisions to the cobra head style street lights. The earliest ones were recognizable by their push button latches to open the bottom cover. The latches were modified by installing a tab to prevent inadvertent opening of the lamp. Later models used different latching mechanisms such as thumb latches that made it easier for utility crews to service the lights.

The light disassembled.

Holophane refractor.	Closeup of the push button latch
Installed as part of the collection.	Another view.