A Bracelet to Measure Sun Exposure Netatmo, the company known for its personal weather station, is getting even more personal about the weather. This spring the company will introduce June, which appears to be a piece of jewelry, but in fact measures sun exposure, telling wearers when to apply sunscreen and when it's time to get out of the sun. The bracelet works with an app. You enter personal information like your skin type, and it observes your habits and measures sun exposure. It then send alerts to help you avoid getting too many skin-damaging rays. The monitor is made from an alloy metal and shaped with jewel-like facets. It can be worn as a bracelet or a brooch and comes in gold, silver and gun metal colors. The price will be $100 when it goes on sale in the spring, the company said.