With the PowerLung Resistance Cell Sets, you now have the flexibility to change the resistance level of any PowerLung model at any time you want!
If you have purchased a PowerLung model and are receiving the benefits you expected from the model you purchased then there would be no necessity for you to purchase a PowerLung Resistance Cell Set for another model of PowerLung now. You might choose to purchase a new resistance cell set at a later time for additional training or for sport specific training.
