The FreeStyle Libre 2 sensor is a continuous glucose monitoring (CGM) device designed for diabetes management in individuals aged 4 and older. ​ It is worn on the back of the upper arm and measures glucose levels in the interstitial fluid every minute. ​ The sensor can be worn for up to 14 days and provides real-time glucose readings when scanned with the reader. ​ It also features optional, real-time glucose alarms for high and low glucose levels. ​ The sensor is waterproof and can be worn during bathing, showering, swimming, and exercise. ​