Asmart center&reg; Newest GPS Watch Tracker GSM GPRS Personal GPS Wrist Tracking System with SOS Function Smart GPS Tracker Wrist Watch This Quad Band GPS GSM Cell phone Wrist Watch represents the perfect combination of GSM and GPS technologies displaying at a touch of a button your exact longitude and latitude coordinates. This GPS watch also comes with a two way calling feature that allows up to 3 mobile phone numbers to be stored. Support single SIM card. Can make a call directly. It is a great gadget for elders and children.