I got a few of them myself now. All are 12". Only one of the 5 works. The second one is balky, flickers a lot.

They are:
Precision Solar Controls Model 2035 19w (11/01) - Doesn't work.

Leotek Electronics Model TSL-EV12G-HP3-A1 12.5w (01/01 - Used to work but half of was dead. Now it's completely dead.

Dialight Model 430-1315-001 Arrow 12.5w - Works but there was a note saying the LEDs are dim. (No idea if that's true since I never had a working traffic light up close.

Leotek Electronics Model TSL-EV12Y-HP1-A1 NC 22w - Works but flickers occasionaly. 4 of the LEDs are dimmer than the rest. (Probably bad solder on that series string. Easily fixed.)

Dialight Model 430-1215-001 23w - Doesn't work.

I got them at the state surplus for a buck each. I plan to head back there but with a power cord with alligator leads to test them at the store to find the good ones.

Normaly I would take a pic of them and post them here but I lent my camera to my mom so I am camera less this week.