All MTI tubs are available with a factory-installed pre-leveled foam base. This facilitates installation by eliminating the need for using a wet-bed compound to level the tub. Adds approximately 2″-3″ to the overall height of the tub. This foam also acts as a sound dampener and barrier. MTI uses high-density closed cell foam which will not shrink, crack or deteriorate over time.
More detailed information and MSRP