1UV Detection: This UV detection sticker reveals whether you have applied enough sunscreen and indicates when it is time to reapply, helping prevent sunburn and sun damage. 2Color Changing: The sticker changes from transparent to purple when exposed to UV rays. As the color deepens, it serves as a reminder to reapply sunscreen for optimal protection. 3Reusable Design: The UV sticker can be reused, with the color change lasting throughout the day. It provides a convenient and cost effective solution to monitor sunscreen effectiveness. 4Safe and Comfortable Fit: The sunscreen patch uses a safe adhesive that ensures a comfortable and secure fit. Suitable for use by both kids and adults without any concerns. 5Outdoor Use: Perfect for beach, park, picnic, hiking, and other outdoor activities, this UV patch offers a convenient and visible way to guard your skin from UV rays.