Callaway Golf Wear UPF30, Sweat-Absorbent and Quick-Drying, Dot Pattern Button-Down Short Sleeve Polo Shirt Item No.: 241-1134460 Off-White / Size L UPF30 is a global index "UPF (Ultraviolet Protection Factor)" that indicates how much clothing can block ultraviolet rays. It means that it has the effect of preventing sunburn for 30 times the time it takes to get sunburned with bare skin. UPF is an abbreviation for Ultraviolet Protection Factor, and it is an index for ultraviolet protection used in clothing. The numerical value ranges from 1 to 50, and the higher the number, the higher the protective effect. Products exceeding 50 are displayed as UPF50+. When wearing UPF30 clothing, it can be interpreted that it takes 30 times longer to get sunburned as with bare skin. For example, if it takes about 20 minutes for sunburn to start on bare skin, wearing UPF30 clothing will have the effect of preventing sunburn for 20 minutes × 30 times = 600 minutes (10 hours). My family wore it once. I am selling it because the size does not fit. Both the collar and the fabric are in very clean condition. As shown in the 7th photo, there is a snag mark, although it is not very noticeable. Please understand that this item has been stored at home and is a used item. Thank you very much. m(_ _)m