This allows you to hook up all kinds of things as an input. It is an invention kit that tricks your computer into thinking that anything is a keyboard. The kit uses high resistance switching to detect when you've made a connection even through materials that aren't . The on-board ATMega32u4 communicates with your computer using the Human Interface Device () protocol which means that it can like a keyboard or mouse. The principle is simple and the function is powerful. No programming, no need to connect cumbersome lines, no need to install software, just need to connect USB to use, simple. Type: main control board Feature 1: Main control board Feature 2: main control board Compatible: For main control board color:As shown Material:PC size:9.4 x 4.8cm Package Contents: 2 x Main Control Board 20 x Spring Clips 2 x 20 x Cable 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.