GPS tracker accessory of fuel sensor, it connect with the vehicle gas box fuel wire, and then detact the reserve of the fuel in real time and send the fuel quantity to tracking device, then device can send this data to control center. It is easy for control center to know anytime fuel quantity information in the gas box and then it can avoid the situation that any driver make wrong reporting of the fuel consumption... This fuel sensor used on gps tracker device ST-G528, ST-G526 and price offer of gps tracker not include the fuel sensor accessory.