Resistance Unit for current Saris and older CycleOps trainers.

• Can be used to replace your current resistance unit or to upgrade your trainer
• Mag Resistance Unit provides linear, magnetic resistance with 5 adjustable levels of resistance
• Fluid² Resistance Unit provides progressive, fluid resistance that is a progressive resistance providing a quiet and consistent ride 
• Must have a Classic Series frame to use these resistance units
• Not compatible with Pro Series trainers
• Jetfluid Pro
• Powerbeam Pro