Sigma Labs Inc (SASI)

[MDuffy]

Technically, they did sell 2 PrintRite machines...

From the 10q:
"We expect to generate revenues primarily by direct sales or licensing our technology solutions to businesses that seek to improve their manufacturing production processes and/or manipulate and improve the most functional characteristics of the materials and other input components used in their business operations. However, we presently make no sales of these technologies and generate no revenues therefrom, except for license fees payable to the Company under the exclusive license agreement with Allotrope, and sales of two of our PrintRite3D® systems to a leading aerospace company for use for test and evaluation purposes with respect to 3D metal printing.

I assume that company was GE, so it is currently being used.