A small, discreet sensor that is worn on the back of the upper arm and continuously measures the glucose concentration in the body's interstitial fluid day and night. The sensor updates the glucose result every minute and stores up to eight hours of glucose readings in 15 minute intervals. It can be worn for UPTO 14 days which means product can last from 0 day to 14 days and is water-resistant so continues to work while you shower, swim or exercise.