Book has stains on pages (See Pictures) The Electrical Apprenticeship Supplement by Mike Holt is a textbook published in 2019 based on the 2020 NEC. This trade paperback book serves as a supplement for electrical apprentices, providing comprehensive content in English language. Authored by Mike Holt and published by Holt Enterprises, this supplement covers various topics within the electrical education field, making it a valuable resource for students and professionals alike. With a focus on general electrical principles, this supplement is a helpful companion for those looking to deepen their understanding of the subject.