Product Overview: micro: bit is an entry level development board designed by BBC for teens programming education. It supports the PXT graphical programming interface developed by and can be used under FOR , MacOS, IOS, Android and many other operating systems without downloading the compiler. It has integrated a 4-way 5V relay module, fully compatible with for micro: bit development board. It can work by inserting micro: bit into keyes relay shield, then inputting DC 5V voltage on the relay VIN GND port, pretty simple and convenient. 4-way relay on the board is active at High. Its control terminals are respectively connected to P4, P3, P7 and P6 of the micro: bit development 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. Description: Voltage input: DC 5V Working Mode: active at High level Contact Capacity: AC120V/3A; DC24V/3A Material: plastic colour: red black Package Contents: 1 x Microbit Expansion Board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.