Robotpark Proto Screw Shield Kit R3 - OEM makes it easy for you to design custom circuits. It is a terminal expansion board that can be screwed directly to the terminal on the thread and is reliable and convenient. Robotpark Proto Screw Shield Kit R3 - OEM has extra connections for all of the Arduino I/O pins. You can the middle of the board as a prototype expansion board. It's a convenient way to make your custom circuit and Arduino into a single module.