This is the bare circuit board from the bus display kit. It is for hobbyists who already have many of the components that are included with the kit. You can save some money if you use components you already have. The computer kit instructions has a complete parts list for the display kit on page 63 that you can refer to. I buy the parts from Jameco Electronics, and you can buy any parts you might be missing from them. If you have any questions about the exact parts you need, contact me and I will help you pick the correct parts.