This is a used King KN 74 Area Nav Computer Maintenance / Overhaul Manual. Installation manual number 006-0056-00, Revision 1, December 1973; Maintenance/Overhaul manual number 006-5047-04, Revision 4, December 1977. This book shows wear - paper yellowing exists, some of the pages are loose and have been placed back in, and there are some handwritten notes in a few places. Photos are a good representation of condition. It cannot be guaranteed that all pages are present, some may be missing. This manual is for reference only. Buyer assumes all responsibility when using.