This Paraffin Oil by Harvia is an oil treatment for wood surfaces that reduces the amount of humidity and dirt absorbed into the benches, thus increasing their life span. We recommend that you treat new benches before using them and repeat the treatment once or twice a year when cleaning the sauna. The paraffin oil is suitable for all wood surfaces, but it is especially good for heat-treated wood and alder surfaces. The paraffin oil is colorless, but it accentuates the natural color of wood surfaces.