Three books in the package that have been revised for the 2020 NEC Code adoption. These are the three books, plus a 2020 NEC codebook (you need to purchase separately) that are used for the Texas Residential Appliance Installers License Prep Course. The three workbooks are available for $150. The one day class includes about 8 hours of  orientation and instruction to help you pass this Texas exam. The current pass rate is about 28%. Many people that have failed the exam prior to taking this course have passed the exam after going through the one day prep course. These materials are not intended to provide all of the information that you need to do the work. These materials are intended for people that are already trained for doing the work, but that need to pass this difficult exam.