In today's demanding world, model flyers need clean, quiet and safe power sources. The CO2 motor has become an important means of meeting those needs. This comprehensive guide to CO2 power will help both beginners and experienced modellers to take advantage of this technology. The basic principles are described and the newcomer is guided through the initial learning process. More advanced motors are also described and the design of CO2 models is discussed in detail. There is a chapter devoted to troubleshooting techniques and another offering advice for the engine collector. Finally, some predictions are made concerning the future development of this technology.