This is the Short bridge, 40.64mm spacing, used for cards that are side-by-side. Example here.
I derived this from my model of the Medium version. I didn't bother measuring this one in as much detail or did the interior parts.
STEP and SketchUp models included in the .zip file.
If you've ever thought to yourself, "Boy, I sure wish I had an excessively detailed model of the NVIDIA 2-way SLI bridge for single slot card spacing", then today's you're lucky day!
Modeled using measurements from a digital caliper, this model should be accurate to about 0.1mm.
Note: This is...