The 4th Edition of the Hot Topics Audio CD has updated and additional hot topics, more on inputs and outputs and references the 4th Edition of RMC's PMP Exam Prep and the PMBOK 2000.Bit expensive for 2 CDs, but very useful The package contained 2 Audio CDs. They are very well made. They are in the format of questions and answers by each of the knoweledge areas of PMP exam. I would suggest using these after going through PMBOK and possibly another book for the exam. I used these towards the last couple of weeks. For the price charged, the CDs seem somewhwat expensive. But there is no other similar product.