Nope, no mag resistance. There is a belt that is connected to the fan and the front roller. As you increase your speed, the fan spins faster, causing more resistance on the fan (just like you experience as you try to go from 20mph to 25mph on the road, more wind resistance). Then, to make the whole thing adjustable, there is a flap on the side that allows you to open or close the fan anywhere from 0-100%. The more you have it open, the more air flows through the fan blades, and the more wind resistance it feels. There is absolutely no way to ever max out your gears with the headwind. Kreitler claims that at 40mph with the flap all the way open, the fan provides an extra 2000 watts. Today I did a 20 minute CP test with the fan about 75% open, and my average speed was around 18 mph at 300 watts.

The fan is great because since its just cutting through fluid, the resistance feels exactly like the road, not the odd feeling resistance that magnetic resistor units provide. In addition, the fan has an extreme out put. I can go all out and never get overheated on that thing.