The free CD with this class on it is available free to schools, teachers and counselors of youth centers or with any Wind Gen Zen purchase of: Our wind generator blade carving CD or A Wind Gen Zen wind generator blade or A Wind Gen Zen generator (PM DC motor) Click here to review Wind Gen Zen products. Download Code: Enter your download code above to download the Free Zip File. This is the Download Code you received with your Wind Gen Zen order. Also a password you received with your Wind Gen Zen order is required to open the Zip File. Note: this class teaches you to run your vehicle on water producing hydrogen, mixed with normal gasoline. Installing this system requires very little modifications to your current system and typically provides about twice the mileage. To obtain a vehicle running from pure water is actually quite simple, but would require a hydrogen storage tank for starting and larger unit - about twice as big. A hydrogen storage tank is not a safe device and this manual does not recommend you try a pure hydrogen car, although if you did, your car would run 100% from tap water - a great idea. Hard to believe? Believe it. The U.S. Military used a similar technology in WW-II running tanks on 100% water in the desert and the diagram below shows a unit made in the 1930's by an Engineer that worked without any fancy electronics. It wasn't as efficient, but it did work. The circuit you'll build for this modification is much more efficient and it really does work!