Recently, Goldcard IC Card and NFC prepaid gas meter, Sigfox smart gas meter, NB-IoT smart gas meter, LoRaWAN smart gas meter series were awarded OIML R137 international metrology certification by NMI. These are the general smart meter types which have been deploying for years since 2012, with total quantity over 10 million with good performance. These are the dual display meters, support digital LCD display, meanwhile retain mechanical counter display, which can be used for tracing basic measuring data. They are suitable for sceneries that sensitive on meter prices, but require basic remote communication for efficient meter reading, moreover, the users are potentially easy to dispute on measuring bills. Its unified structural design adapts to a variety of communication technologies, and quick response can be achieved through factory configuration.