Comparison between the ATBS and ATBM

The components are the same besides the driver brand and arrangement of the gear inside. Notice the weird spot for the bubble level on the larger unit... it's on the driver!

Notice that the ATBS's single glass optical is larger than the three glass optics on the ATBM. I had assumed the ATBM used three of the ATBS's glasses, but turns out it's a single piece glass with three globes molded in. The three globes are essentially shrunken down copies of the larger single optical.

Note that although the ATBM has the option for a 4-bolt fitter, only 2 bolts and one bracket are present. Don't really need 4 bolts with the leveling steps anyway...

As for size difference, the ATBS is around 24" long while the ATBM is just shy of 28". Ironically the ATBM medium fixture is around the same size as a typical small size cobrahead, which just shows how small the ATBS is lol. The "white circle" on the ATBM on the right is 13" in diameter, compared to the 10" of the ATBS (seems like way more of a difference though, right?).