One of Florence&rsquos most frequented sites, the Cathedral of Santa Maria del Fiore (Duomo) is the first museum complex in the world to execute the usage of social distancing necklaces for its visitors. The EGOpro Active Tag, developed by the Florence-based company Advanced Microwave Engineering, uses radio technology to sense the measure between two tags. The device will flash, vibrate and softly beep when one visitor accidentally walks within two metres or 6.5 feet of another, signalling they are too close. However, if a person is travelling in a group, the necklace sensors can be pre-calibrated so they can walk without setting them off.