For ESP8266 ESP12E Compatibility: This expansion board is designed to work with ESP8266 ESP12E and is fully compatible. GPIO expansion One GPIO into two: Expands a single GPIO pin of a Development Board to two accessible connections, enabling convenient pin reuse for larger smart home projects and complex wiring. Two connection methods Two connection options: Pin Header Connector and Screw Terminal. Choose the method that fits your wiring needs and project purpose. Doublelayer PCB Stable construction: The board uses a doublelayer PCB with one pin wired on both sides, delivering a more reliable connection and stable signal transmission, reducing the risk of poor contact or instability. Key benefits Simplifies wiring by duplicating a GPIO to two connections, aiding complex setups without losing a single pin. Flexible installation with two connection methods for easy prototyping and final deployment. Durable and reliable signal integrity thanks to the doublelayer PCB design. Use scenarios Smart home projects: Split a single GPIO to drive two peripherals (for example, a sensor and an actuator) from one development board pin. Prototyping and testing: Quickly switch between pin header and screw terminal connections to compare wiring approaches or to simplify breadboard and permanentwiring transitions. Educational or lab environments: Demonstrate GPIO multiplexing and wiring options without needing extra modules or adapters.