Product Overview: : 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 Windows, 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 : bit development board. It can work by inserting : 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 : 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. 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.