Before buy, please check There is no difference between 2G TK905 and 4G TK905 in appearance function and quality. Their difference is only in the network. The 3G TK905 supports 3G networks, and the 2G TK905 is only compatible with 2G networks. USA, Australia, New Zealand, Korea, Japan, Canada, Singapore, Taiwan; Customers in these countries, please choose the 3g version. Your country has closed the 2g network. Customers in other countries, you can choose at will. 4G TK905 GPS Tracker GSM SpecificationGPRSClass 12, TCP/IPMemory32+32MbPhase errorRMSPE<5,PPE<20Max outputGSM 850/GSM 900:333dBmGSM 1800/GSM 1900:303dBmMax frequency error0.1ppmLTE SpecificationOperating band LTE Cat-M1/NB2: B1/B2/B3/B4/B5/B8/B12/B13/B18/B19/B20/B26/B28/B66Data transmissionLTE Cat M1: Max. 588kbps (DL), Max. 1.119Mbps (UL)LTE Cat NB2: Max. 127kbps (DL), Max. 158.5kbps (UL) EGPRS: Max. 296kbps (DL), Max. 236.8kbps(UL)GPS SpecificationGPS chipsetMTK high sensitivity chipFrequencyL1,1575.42MHz C/A codeGPS channel66Location accuracy<10 metersTracking sensitivity -165dBmAcquisition sensitivity-148dBmTTFF (open sky)Avg. hot start1secAvg. cold start40s