This is a brand new set of 3 OS X 10.7/10.8 Lion/Mountain Lion Apple Training Series/Quick Reference study guides by Peachpit Press. These were typically used to prepare for the Apple Certified testing. They originally sold for between $39.99 and $64.99 each, or $169.97 for all three. This is the list of titles: OS X Lion Server Essentials, Using and Supporting OS X Lion Server, Authors Alex Dreyer and Ben Greisler, ISBN: 0-321-77508-2 OS X Support Essentials, Supporting and Troubleshooting OS X Mountain Lion, Author Kevin M. White, ISBN: 0-321-88719-0 OS X Mountain Lion, A Quick Reference Guide to Mastering your Mac, Author Lynn Beighley, ISBN: 0-321-85851-4