DNA-photolyases use UV-visible light to repair DNA damage caused by UV radiation. The two major types of DNA damage are cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts (6-4PP). which are repaired under illumination by CPD and 6-4 photolyases. respectively. https://www.lightemupsequences.com/hot-mega-Esko-Nexus-HeightMaster-Vented-Safety-Helmet-big-savings/