Details：
When using this phone to make a call, you need to place the phone card in a special card sleeve, and then insert the card sleeve into the phone card slot. After the signal is detected, you can make a call. It is mainly suitable for areas where mobile phones are not allowed. Support lock network lock card.
Details：
Square-Curve-Crystal Head
Details：
Square-Turn Curve-4Pin Interface-Frosted
Details：
Square-to-curve-audio interface
Details：
Square-to-curve-USB interface
Details：
Square-to-curve-4Pin interface
