标有PA的产品是针对UVA的，这样防晒品会发挥更加有效的作用，通常情况下，PA的强度用+来表示，多一个+表示有效防护时间延长。
The product marked with PA is for UVA, so that sunblock will play a more effective role. Usually, the intensity of PA is represented with +. An extra + indicates extension of effective protection time.