This wireless communication module is integrated with GPRS Module SIM800L. It is a custom ESP32 (ESP-WROVER-B 8MB PSRAM) based development board. The TTGO wireless module uses UART, SPI, SDIO, I2C, LED PWM, TV PWM, I2S, IRGPIO, capacitor touch sensor, ADC, DACLNA pre-amplifier modulear interface. It has working voltage of 2.7V-3.6V and supports Nano SIM card.
The ESP32 based wireless communication module is best for IOT applications because it consist of USB Type C pluggable board that has an onboard LiPo Battery Charging Circuit & Connector.