The protection factor, abbreviated as SPF (Sun Protection Factor), indicates how many times longer the skin can be exposed to sunlight before it reddens, compared to not using a protective product. Products with a factor of 50 and above block approximately 98% of UVB radiation, which is responsible for sunburn. Such a level of protection is suitable for individuals with very fair and sensitive skin, for small children, or for staying in places with high sun intensity, such as high mountains or areas around the equator. However, even a high factor does not provide one hundred percent and all-day protection, so it is necessary to reapply the product regularly.