Description: Keyestudio micro bit relay shield has integrated a 4-way 5V relay module,fully compatible with micro bit development board. It can work only need to insert mivro bit into keyestudio micro bit relay shield, then input DC 5V voltage on the relay VIN GND port,pretty simple and convenient. 4-way relay on the shield is active high.Its control terminals are pespectively connected to P4,P3,P7 and P6 of the micro bit develpment board.You only need to control the high or low output level of P4,P3,P7 and P6, thus control the 4 relay on/off. With functional testing, voltage and current testing, all our boards are fully qualified before selling. Adopting environmental-friendly components and production technology to ensure product safety, our products have passed the United States FCC certification and the EU CE certification, authentically and validly. Specification: Material: Fr-4 epoxy Plexiglass Fiberboard Size: approx. 8 x 5.7 x 1.3cm Package Includes: 1 Piece Relay Breakout Board Note: Color maybe slightly different due to different monitor. The above size is measured by hand, please allow slightly difference. Thanks !