The Calculated Industries ElectriCalc Pro NEC Upgrade Kit supports NEC Code years 1996 through and including 2011. This upgrade kit is a response to several impacts found in the 2011 NEC code in relation to the ElectriCalc Pro calculator. Use this kit to make your ElectriCalc Pro NEC 2011 compliant. It includes an easy to follow User Guide with step by step instructions. Following installation, your calculator will continue to be completely upgradable to future NEC code changes.