Freestyle Libre Sensor Glucose Monitoring System - The Freestyle Libre Sensor is small and discreet. Easily Applied: Using the supplied disposable applicator, the FreeStyle Libre sensor can be easily applied and stays on the back of your upper arm for upto 14 days. Work Seamlessly : The FreeStyle Libre Sensor can even be worn while you shower, swim, bathe or exercise, so it fits seamlessly into your lifestyle. Factory-calibrated : FreeStyle Libre is the only factory-calibrated glucose monitoring system. You don’t need to recalibrate it again and again with painful fingerpricks. No fingerprick : The FreeStyle Libre system is accurate, stable and consistent over 14 days without any need for fingerprick calibrations.