MPVI4 is HP Tuners' flagship OBDII interface for vehicle tuning and diagnostics. This device plugs into a vehicle's OBDII port and connects to a user's laptop with HP Tuners' VCM Suite software package, combining VCM Scanner and VCM Editor. Together, MPVI4 and VCM Suite provide users the ability to scan, data log, read, edit, and write to their vehicle's control module(s). MPVI3 is built for professional calibrators and DIY enthusiasts alike. Pro is the new standard with MPVI4. Take advantage of Pro Feature Set capabilities like standalone data logging and PROLINK+ compatibility (sold separately) already built into your new device. MPVI4 redefines the limits of speed and control with faster standalone data logging and 2X the storage capacity compared to the previous generation. Log more runs (faster) and store more calibrations on your MPVI3, all with the convenience of eliminating your laptop from the equation.