UPF50+ refers to a standard for ultraviolet (UV) protection, indicating that a product can block more than 98% of UV-B and UV-C rays. UPF (Ultraviolet Protection Factor) is an indicator of the efficiency with which clothing or materials protect against UV rays. When the UPF value is 50+, it means that the product can effectively block approximately 1/50 of UV rays from penetrating the clothing or knitwear. According to national regulations, the maximum UPF value for textiles is 50+; values exceeding this limit pose very little potential harm to the human body.