This is a two pieces (per corner) 6mm standoff with a selection of mating glass clamps. The 6mm gap is to add insulation.
I have 1.3 mm glass which is a little narrow so I have wider clamps for it.
I have added clamps for 3mm as well.
This design is for long glass (picture frame glass). If the glass was the right size you might do it differently.
The SU has a few other parts I was playing with - single piece holders that didn't really work.