Did you know,all GE cobraheads have the same holophane glass lens.
 

No. GE used many different glass lenses. Holophane did make all the variations, but to say all the lenses are the same isn't true.

I dont know what the part #'s are or the proper name for these GE globes, but i do know there were 2 types of curved glass globes and 1 type of larger plastic globe used on all the GE M400 series fixtures (up to 1996) and all GE M250 series fixtures.

There are at least 4 refractor footprints alone just for the cobras, the first would be for the M400, M400A, M400A2, M400R2 and other related fixtures. The second was for the M250, M250R, M250A, M250R1, M250R2, M250A2 and others. The third is for the M1000. And the fourth is for the M400R3 and M400A3. For each footprint there are dozens of styles and materials for the refractors, never mind the clam shells and other fixtures.

I forgot about those other 3 GE lenses.I was thinking about the holphane lenses.