Sum & Substance Audio CD Series allows you to assimilate the essentials of the course at your convenience - listen while working, commuting, exercising or just relaxing. The information and ideas you struggled with previously are now brought to life simply and succinctly. The CD provides Quick Reference Indexing, allowing you to quickly locate every topic in the entire recording. Also provided are exam tips to maximize your performance and Lifetime guarantee. These CDs are time saving, convenient and effective.