12mm x 2.0mm Quartz Tube - Approx. 4' L

I bought 8 feet of this tubing to use as a kiln element insulator. I assumed that the 12mm dimension listed was ID, as is the case with most other types of pipe/tubing, but when it arrived I discovered this tube was 10mm ID, 2mm wall thickness, 12mm OD. No problem, wound my element to fit inside of a 10mm tube, put everything together, and fired it up. This tubing handled a temp rise from 53f to 1050f in about 10 minutes without any cracking or deformation, just as quartz tube should.