Less than half the size of the PCIII USB. USB powered from computer (9V adapter no longer needed for programming). Two-position map switching function built in (map switch not included). Gear/speed input allows for map adjustment based on gear and speed. Analog input allows user to install any 0-5V sensor and build an adjustment table based on its input such as boost or temperature. With gear-postition connected, the PCV is capable of allowing each cylinder to be mapped individually and for each gear. Unit has a -100/ +250% fuel change range (up from-100/ +200%), which allows more adjustment. Ten throttle position columns (up from nine on PCIII USB). Enhanced “accel pump” utility (increased adjustment and sensitivity ranges). Made in USA.