Check the listing for details. VoltSwitch GPS VOLT-SL78 4G Wireless Tracking Device Magnetic. Condition: New, Made in China. Listed at 23.96 USD. The VoltSwitch GPS VOLT-SL78 4G Wireless Tracking Device is a reliable and efficient tracking solution for vehicles. With its magnetic feature, it securely attaches to the vehicle for easy installation and removal. The 4G wireless technology ensures fast and accurate tracking, while the VoltSwitch brand ensures quality and dependability. Whether you want to track a personal vehicle or a fleet, this device provides real-time location updates and alerts for added security.