The Jet Black Z2 Fluid trainer is a high quality and smooth trainer that provides a quiet and realistic ride feel in comparison to other turbo trainers. The proprietary fluid in the JetBlack Z2 Fluid increases resistance exponentially up to 900 watts. The faster you spin the harder it gets. Get the most out of each and every ride with JetBlack's Z2 Fluid Trainer. The Z2 design offers a wide range of resistance, allowing you to tune your session by adjusting your gears the same as you would on the road. The Z2 is the best value trainer regardless of whether you're spinning out a recovery ride or undertaking an intense threshold workout.