Carbon Elite Hard-ULTRA (Lithium)Carbon Elite Hard ULTRA is an extremely easy to use Nano Silica densifier specifically designed for concrete polishing and is an integral part of the Carbon Elite Floor System. Applied during the polishing process, this impregnating hardener improves the final appearance by creating a significantly harder surface that allows abrasive tooling to work more effectively and to achieve a superior polish. Carbon Elite Hard ULTRA increases gloss and clarity,