How many Sf4000 versions are on the market?

[gristle]

Lifelong hps'er but curious enough now to give leds a test. Came across a NIB sf4000 for sale by friend's friend. How many versions are there and any glaring differences? And any way to tell them apart at a glance?
Thank you guys in advance.

 

[Dirtbag]

I think 3? There was the original that had no external dimming function, the 2nd was the same but has external dimming knob, and the 3rd has that as well as an improved diode layout. #2 and 3 can also be daisy chained.

This is what you will see on the newer models. It is the external dimmer with daisy chain capability for linking several lights together. First Gen didn't have this.

You can see it mounted on top between the drivers.

And the final most recent model, the diodes are concentrated in the corners to improve light spread.

 

[gristle]

This is the only picture he sent. He said it did have the dimmer although.
Double thanks dirtbag for the info and the 'popping a tent' thread which has inspired me to try something new.