... S D card Antenna inside GNSS dual-frequ SpecificationSatellite Signal L1/L2/L2C/C/A P, ... , for the user of surveying and GIS.Dual-frequency Antenna Tracking, Excellent Performance:The host ... expeditely, even in the case of low network signal.Compact, Light, Flexible and Convenient:Integrating directly ... , even in the case of low network signal.Compact, Light, Flexible and Convenient:Integrating directly ...