UV exposure is a big issue for people, so beauty giant L’Oreal has disrupted the fashion and technology worlds by unveiling “My UV Patch.”

It’s a heart-shaped “stretchable sensor” with a one-inch diameter that can be worn on the skin anywhere and, with the help of your phone, can tell you how much UV exposure you are subject to at what times of day. It lasts five days and can be worn from the shower to the beach and then tossed.

The patch is the first of 10 wearable devices L’Oreal is making in partnership with Irish product engineering firm PCH. The techno-fashion statement was unveiled in Las Vegas at the International CES, the annual consumer electronics show.