Osmo uv-protection-oil extra is a satin, Clear finish for exterior. It is based on natural oils, is microporous, and does not crack, flake, peel or blister. When used as a final finish after staining wood, Osmo uv-protection-oil extra prolongs the renovation time significantly. As a stand alone finish, with two coats, It prolongs the greying process on vertical surfaces by up-protection factor 12 compared to untreated wood. The finish contains active ingredients which protect it from mould, algae and fungal attack. Easy to renew, no sanding or primer necessary. Easy to apply, will not dry during application.