PiFace Digital I/O Expander Plugs directly onto the Raspberry Pi GPIO socket Fits Directly over the Raspberry Pi and within the Raspberry Pis footprint 2 Changeover Relays 4 Tactile Switches 8 Digital Inputs 8 Open-Collector Outputs 8 LED Indicators Easy to program in Python, Scratch and C. Graphical Emulator and Simulator Relays can be used to switch voltages up to 20V (Max) or currents up to 5A (Max)