Gatorade is today releasing a new fitness wearable that tests your sweat to let you know how and when to best rehydrate after working out. The Gx Sweat Patch is sold in packages of two for $25 and pairs with Gatorade’s Gx app to let you efficiently hydrate and hopefully recover faster and avoid cramps in the process.

The sweat patch is applied to your left inner arm before a workout and slurps up sweat as you move, funneling the fluid through a color-changing channel on the patch. After you’re done working out, you use the Gx App to scan the patch. Gatorade says it’s able to offer insights on how much body fluid was lost and how much sodium needs to be replenished (presumably with Gatorade) to recover efficiently.

Image: Gatorade

The Gx app also attaches these hydration insights to specific workouts, so you should theoretically have a recommendation of how much to drink before, during, and after every 10-mile run you do, if you’ve created a sweat profile for it in the app.

Even with all of the polished Gatorade branding, $25 for a package of two patches puts the individual price around $12.50, which seems high considering a patch can only be used once. Gatorade imagines using a patch for each of the workout types that someone does, so if you only play basketball and run, maybe a single $25 purchase is enough. But Gatorade also recommends creating a new sweat profile for each climate or temperature you work out in. So the more ways and places you exercise, the more you may need to spend to accurately hydrate and recover efficiently.

Image: Gatorade

The Gx Sweat Patch may seem a little unusual, but for a world increasingly comfortable with all sorts of biometric fitness tracking, it seems like a logical next step for a serious athlete. It’s a way for Gatorade to sell more Gatorade, but depending on the person, the possible annoying upsell of future Gatorade products might be worth the extra knowledge.