Innovative idea. While I don't plan to buy, here are a few more technical details from the vendor's site.
"We use Almag 535, a light weight, high performance, high strength Magnesium Aluminum alloy and wall thicknesses of 1/2 inch or more to evenly distribute load throughout the jack stand base. The results are jack stands that meets ANSI standards at 4000 pounds and a stable base nearly twice as wide as conventional jack stands."