Reacts to the sun’s rays · Turns purple when it’s time to reapply sunscreen
These UVA/UVB awareness sensor dots alert you when it’s time to reapply sunscreen. Just stick a dot on when you apply your sunscreen. Its biopolymer layer will absorb the sunscreen and react like your skin does when it’s exposed to sunlight. When the dot turns from clear to purple, you know it’s time for more sunscreen.