Purpose and key benefit Expands a single ESP32 GPIO into two outputs, letting you reuse pins for additional sensors, relays, or indicators without rewiring the main board. A compact, reliable alternative to repeated breadboard wiring in smart home and prototyping projects. Connection options Two connection types available: Pin Header or Screw Terminal. Choose the type that matches your wiring style and project needs. Board construction and performance Double-layer PCB with each pin routed on both sides for improved signal integrity and electrical reliability. This reduces the risk of poor contacts and unstable signal transmission in finished projects. Compatibility (important) Designed only for the 38-pin narrow ESP32 version without mounting holes. Not compatible with other ESP32 versions or models. Practical advantages Saves GPIO pins by duplicating one pin into two accessible connections. Stable wiring and reduced connection failures thanks to the double-layer design. Clear connection options for soldered or screw-terminal wiring, supporting different installation preferences. Typical use scenarios Smart home: add an extra sensor or status LED to an ESP32-based thermostat or lighting controller without sacrificing an existing GPIO. Prototyping: use as a tidy breadboard alternative to split a GPIO to two modules during development and testing. Embedded projects: provide a secure screw-terminal connection for field installations where connectors need to be removable and robust. What’s included / notes Expansion board with double-layer PCB. Connection type supplied as Pin Header or Screw Terminal according to your selection. Verify you have the 38-pin narrow ESP32 without mounting holes before ordering to ensure correct fit and function.