Technical Specifications - CPU: Tensilica L106 32-Bit Processor (ESP8266) - Connectivity: Wi-Fi 802.11 B/G/N - Gas Sensor Support: MQ-135 for Air Quality or Any Other 5 V MQ Analog Gas Sensor - Peripherals: Mini OLED Display, UART Pins for Flashing Custom Firmware, Button, Three Slots for I²C Sensors - Compatibility: Arduino IDE, PlatformIO, Home Assistant, OpenHAB, ThingSpeak, MQTT, and Any Modern Web Browser - Certification: Open Source Hardware Association (OSHWA) BG000018 - Dimensions: 75MM x 40MM