This fluid resistance trainer encases its resistance unit in a hydraulic fluid that gets the fluid hotter therefore more resistance the harder you pedal. The exclusive Power Band Technology offers the widest resistance range from easy spins to lung-burning climbs without ever touching the unit. An infinite resistance curve ensures increased wattage as you increase speed. A self cooling mechanism included a patented fan design for an ultra quiet ride improves durability and keeps the unit performing better longer. It folds up and comes with a quick lock bike mount and customer skewer. Included is a CTS DVD. Dark grey.