Feature:1. Safe Development: This ESP8266 development board is safe and reliable, and can be extended to various application scenarios.2. Smart Expansion: Expanding the GPIO pins on a development board to two greatly facilitates users to reuse pins for large scale intelligent projects.3. Better in Design: The expansion board adopts a double layer design with pins on both sides, providing good stability and high reliability.4. Perfect Matching: Highly compatible for ESP8266 ESP-12E development board, for NODEMCU V2 GPIO expansion board.5. Easy to Install: Light in weight and compact in size as well, the convenient installation can be quickly completed in minutes.Specification:Item Type: ESP8266 Development BoardMaterial: FR-4 materialBoard Size: Approx. 63 x 63mm / 2.48 x 2.48inCompatibility: For ESP8266 ESP-12E development board, for NODEMCU V2 GPIO expansion board. .Package List:1 xESP8266 Development Board