Parallax 28803 Board of Education Full Kit USB version Mechanically interlocked power supply to prevent dual connection of wall-pack and 9-volt battery. Usb connector for bs2-ic programming. P0 - p15 i/o pins. Vdd and vss connections brought adjacent to 5. 1 x 3. 5 cm (2" x 1 3/8") breadboard area. Includes set of ten (10) color-coded 22 gauge wires.