For the 4G version of the T-Box and GPS tracker, for better frequency band coverage on 4G and 3G frequency bands, we can customize different module for different country mobile company & different frequency band, for customized module can get better signal for 3G & 4G, before placing order please tell us your M2M SIM card or normal mobile phone SIM card company, also you can call your SIM card supplier or mobile phone company or visit the supplier website can get the frequency band information, then we can customize samples or mass products for clients,  The following table shows some frequency bands of some modules, the different module can cover different frequency bands, the module model is over 100 different model, please contact our sales and R&D engineer to confirm the coverage bands.

Suit for Model:CC-338/CC-368/CC-688