This board makes connecting wires to the Raspberry Pi GPIO incredibly easy. It\’s a reference board that makes it really easy to see if you\’re connecting your wires correctly. We liked the Pi GPIO Reference Board from Low Voltage Labs so much that we worked with them to license their design! We made some changes to the low-voltage version – including grouping the pins into categories like I2C, IO, UART, SPI, and power. It\’s only 0.8mm thick, idiot-proof (you can\’t put it on backwards…), and makes a great keychain for the Pi enthusiast. Simply slide it onto the 2 x 13 GPIO header, and then you can plug in premium jumper wires with female sockets on top as shown. This version works with the Raspberry Pi Model B. It does not work with the Raspberry Pi B+, 2, 3, 4 and 5 but we do have a version for them as well! Please note, on Revision A we made a typo! The pin labelled #21 should be labelled #21/27 and the pin below it should be labelled #22! Note: Raspberry Pi and cables are NOT included Specifications Dimensions: 45mm x 20mm x 0.8mm / 1.8\” x 0.8\” x 0.03\” Weight: 1.4g