The ZYCOO CooVox 4WCDMA Module is designed with the SIM5320 series module. SIM5320 is a Dual-Band WCDMA and Quad- band GSM engine that works on frequencies UMTS 850MHz, UMTS 900MHz, UMTS 1900MHz, UMTS 2100MHz, GSM 850MHz, EGSM 900MHz, DCS 1800MHz and PCS 1900MHz.