Osmo UV Protection Oil Extra is a clear matt wood finish based on natural oil for wood in outdoor areas including doors, windows, window shutters, carports, timber cladding, balconies, fences, pergolas, summer houses and bamboo poles (e.g. in screens). Rich in active ingredients to protect the coating against mould, algae and fungal attack, the Extra range offers additional protection in comparison to the regular UV Protection Oil. This UV protecting wood oil works by creating a microporous surface allowing the wood to breathe and reduce swelling and shrinkage. Water-repellent, it will not crack, peel or flake either. Used as a top coat on already colour treated wood, Clear 1420 Osmo UV-Protection-Oil reduces the time to reapply significantly. It blocks the greying process with a UV protection factor 12 in comparison to untreated wood when two coats are applied. We recommend a coloured base coat first such as the Osmo Natural Oil Woodstain or Osmo Country Colour. Preparation and Application.