This article originally appeared on health.com.
You know that you’ve got to protect your skin from the sun’s penetrating rays, but have you ever wondered how much sun exposure you’re actually getting? Thanks to a clever new product from the beauty giant L’Oreal, you’ll soon be able to measure your sun exposure with the help of a high-tech sensor called My UV Patch.
The company—more commonly known for its makeup products—unveiled its foray in wearable tech today at this year’s Consumer Electronics Show in Las Vegas. The patch looks almost like a band-aid, and contains photosensitive dyes that change color when exposed to the sun’s skin-damaging ultraviolet (UV) rays, according to a press release. The stick-on is stretchy, disposable, and can be placed anywhere on the body for up to five days.
Wearers can then upload a photo of their patch to the My UV Patch app, and get feedback about exactly how much UV exposure their skin received. The idea is that people can use the information to inform the level of sun protection they need.
The company is still mapping out the distribution strategy, but the patch will likely be at no cost to consumers.