Saris CycleOps 3 Level Climbing Block for Indoor Bicycle Trainer Black Stackable

Saris CycleOps 3 Level Climbing Block for Indoor Bicycle Trainer Black Stackable For a stable, worry-free ride in any rear-mounted trainer. Unique 3-level design lets you select the level of difficulty. Stack two blocks to simulate climbing workouts. Injection-molded construction is virtually indestructible. Use 2 blocks for 12 different adjustment levels. Patents issued and pending.