I got this Sandisk Pro-Dock 4 card reader holder and laptop dock a while back for a bargain, hoping it would be somewhat slapdash in its electronics such that I could “convert” it to be used as a simple USB 3 card reader apparatus. Turns out, it’s so Thunderbolt that Zeus himself is scared.
The engineers at Sandisk (and/or Western Digital) did an absolutely masterful job with this hardware, though the product appears to have been let down by poor software/driver support. It seems to be discontinued now, which is a shame.
In this video, I tear down the thing and check out its components. Relatively high-res photos of the two internal circuit boards:
