The KMS wristband is a safety device for children and vulnerable adults based on GSM cellular and assisted GPS technology. The wristband enables the wearer to initiate a cellular call to one of up to 5 predefined carers with a one touch button. Carers can track the whereabouts of the wearer from a smart device/web app utilising GPS technology. Carers can also set predefined travel routes and out of bounds areas using the geo fencing facility.