This 5 litre Sika stone protector is a clear water-based sealer suitable for all forms of natural stone. It can be applied internally or externally to protect from staining and discolouration over time. This helps maintain the same new look of the stone surface. Natural stone must not be treated like cement based products. It is good practice to first test a small sample to check for compatibility with previous coatings. Can be used on Indian sandstone, granite, limestone and slate.