Details：
Users can only dial numbers in the whitelist system, and non-whitelist numbers are prohibited from dialing. You can enter whitelist numbers in batches, set the validity period of the numbers, add packages that are charged monthly/quarterly/yearly, etc., and automatically stop the service when they expire.

Details：
you can set free rates, packages; real-time display of phone status; card issuance, card replacement, loss report, recharge; set family number; support WeChat terminal; query call records, etc. Features.

Details：
The phone needs to have a built-in mobile phone card (with data and call charges) or an Internet of Things card to use. If you use a telecom 4G card, you need to activate the high-definition voice call function; you can set free rates and packages; real-time display of phone status; card issuance, card replacement, loss report, recharge; support WeChat terminal; support mobile app; query call records, etc. Function.

Details：
The phone has a built-in mobile phone card, and the user can hold the card and insert the card to dial. Support 13.56M radio frequency card, ID card, CPU card, IC card; support network lock, lock operator, encryption card function, prevent illegal card use.

Details：
The phone is connected to the phone line, and the user holds a valid card and inserts the card to dial. Support 13.56M radio frequency card, ID card, CPU card, IC card; support setting rate; support setting card city code, unit code and sector number, etc.

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.