It is a taillight bike GPS Tracker, built-in GPS Antenna and GSM Antenna, Size: 70x55x20 mm, Weight: 75g, it can send bike location and status to mobile and Internet. It can track the bikes remotely. Track the bike on the computer Web and mobile APP. 1.1 Features1 Real time location tracking2 Tracking by Web or APP or SMS command3 Over speed alarm4 Vibration alarm5 Low power alarm6 Remote voice monitoring1.2 Specifications Item Descriptions Dimension 70x55x25 mm Weight 75g GSMFrequency 850 or 900 or 1800 or 1900Mhz GPS Module MTK2503D GPSSensitivity -159dBm GPSAccuracy 10m Time to first fix Cold start32s Warm start30s Hot start1s Workingcurrent 35mA Battery Built-in3.7V 1500mAh StorageTemperature -40C to and85C Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.