When buying this kind of umbrella, you should buy some dark colors, such as black and brown, because it can absorb more light.
Sun umbrellas can block about 70% of ultraviolet rays.
When buying an umbrella, you should pay attention to whether there is a label indicating that the umbrella is anti-ultraviolet, which means that the umbrella can really prevent ultraviolet rays (ordinary umbrellas can't actually prevent ultraviolet rays). Of course, there are also dual-purpose umbrellas that are both rain-proof and ultraviolet-proof. Usually the label will be sewn on the inside of the umbrella near the skeleton, or the price tag will indicate why the ultraviolet protection function is the same as that of the umbrella, and the price difference will be so great.