... signal Provide RMS Support extended accumulat gsm fixed terminal gsm fwt fixed wireless gsm terminal DetailsFeatures Simple to install / ... (SIM 1 + SIM 2), 3 standby channels (GSM A + GSM B + PSTN) 5 working modes can be selected ... external charge current) GSM parameters Frequency bands: GSM 850MHz, GSM 900MHz, GSM 1800MHz GSM 1900MHz, GSM 850/1900MHz, GSM 900/1800MHz, GSM 900/1900MHz Frequency ...