The material I use in the video is available from many plastics companies online or from specialty stores locally. Mine came from Tap Plastics and is listed as “clear extruded acrylic square tubing.” I use the 1-inch OD (outer diameter) size.
This is a simple, cheap, effective solution to standoff mounting. As you'll see, it won't take the place of the finest commercial systems, but it has a place of its own and deserves due consideration when the nature of the glass, the buyer and the price point all call for simplicity and affordability. Put it to work!