Why are they so useful while working out? Often, you can damage your sensor while working out - that's why you need to protect your sensor. The best protection for your sensor is Freestyle Libre Adhesive Patch by FixiC. Our patches are made from premium materials: cotton with a hypoallergenic acrylic adhesive (no latex or medications) so you can be sure that they reduce skin irritation. You can work out without worrying about sweat damaging your sensor because Freestyle Libre Adhesive Patches by FixiC are waterproof. Make your life easier with FixiC!