Tenax Protex is one of the top premium sealers on the market today. Tenax Protex is suitable for the treatment of all types of stone. Tenax Protex works extremely well on smooth stones, such as Pietra Leccese, Pietra Vicenza, limestone, and similar stones for both indoor and outdoor. After the application a light increase of color can be seen but depends on the type of stone and where the product is applied. UV Stable.