LensAlign Fusion Integrated AF Calibration System Includes LensAlign MkII (Gen4) and FocusTune V4.0 Software License Key Adjust the Auto-Focus Fine Tune and Micro-Adjustment on compatible DSLRs Improve the "out of box" auto-focus performance of your compatible DSLR Ensure precise camera to target alignment required for proper AF evaluation Simple Assembly - Under 5 min, no tools required.