Tired of those teenie weenie trainers that don't make you work very hard? Here is the resistance and kool comfort you've been waiting for- the infamous Killer KOOL Headwind Fan! An adjustable inlet cover allows you to vary the resistance from a 2mph tailwind to a 10mph headwind. The Killer KOOL Headwind is enough to make even the strongest riders beg for mercy. Recent studies indicate that training with an airflow directed at the rider is far healthier than training in still air.