Mineral Wool Pipe and Tank Wrap Insulation with FSK facing is made of inorganic fibers derived from basalt, a volcanic rock with a thermosetting resin binder. Mineral wool pipe and tank is custom fabricated with high fiber density for excellent performance in high temperature and thermal control.  The 2" and 3" thick mineral wool pipe & tank wrap with FSK facing are stock items. All other sizes are made to order, and lead time to ship is approximately one to two weeks from date of order and the product is not returnable.