Guardian™ Sensor 3, our most advanced and accurate sensor, provides an option that fits every lifestyle. Diagnostic chip that automatically monitors sensor health every 5 minutes to improve sensor performance and reduce variability. Each Guardian Sensor 3 glucose sensor can be worn for up to 7 days at a time. Guardian Sensor 3 Glucose sensors have a 12 month expiration date from the time they are manufactured ( Enlite 6 months). Easy to insert. Flexible design moves with your body for ultimate comfort.