1,Compatibility: Based on for RasPi 40PIN GPIO interface, designed for RasPi series mainboards, this expansion module board supports various network communicating protocols including TCP IP, HTTP(s), MQTT(s), FTP(s), and SSL, ensuring seamless connectivity. 2,Enhanced Functionality: With support for dial up internet access, phone calls, SMS messaging, LBS base station positioning, and GNSS location services, this board provides a wide range of practical features. 3,Voice Output Capability: Featuring TTS text to speech functionality, this GSM GPRS GNSS HAT module can convert Chinese or English text into speech output, making it ideal for applications requiring sound feedback or alerts. 4,Versatile Connectivity: Equipped with USB and sound interfaces, this A7670E module board allows for easy testing of AT commands, internet communicating, and sound recording or playback, as well as connection to external control boards like for ESP32. 5,Convenient Design: The GNSS expansion board includes a SIM card slot supporting both 1.8V and 3V SIM cards, as well as two LED indicators for monitoring module operation status, making it user friendly and easy to use. Item Type: Expansion Module Board Material: PCB Weight: Approx. 146g or 5.2oz Product Size: Approx. 65x30.5mm or 2.56x1.2in Operating Bands: LTE Cat 1 LTE FDD: B1, B3, B5, B7, B8, B20 2G: GSM, GPRS, EDGE: 900, 1800 MHz GNSS: GPS, for Beidou, for GLONASS Message and Sound Features: Supported types: MT, MO, CB, Text, PDU Message storage device: USIM card, CB does not support saving to SIM card Sound feature standard: 3.5mm headphone jack, can be used for sound input and output 1 x Expansion Module Board 1 x USB Cable 2 x FPC Antenna Assembly 1 x GPS Antenna 2 x Screw Pack Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.