There is no off-season with JetBlack's Z1 Fluid Trainer HydroGel Roller. This training partner is always up for a session with smooth, progressive resistance from 5 to 900 watts that automatically adjust when you change gears or up the speed! The HydroGel roller gives you increased tire grip with no slippage for realistic "on-the-road" feel. It also reduces noise and is significantly easier on your tires. The CNC'd head gives you super efficient cooling, and the dual retention system makes for solid, precise wheel alignment, security, and stability.