The objective is to conduct a human factors validation study to demonstrate that the user interface of TOBI® Podhaler™ can support safe and effective use for the intended users. The human factors validation study will be conducted in patients with cystic fibrosis aged 6 years and older under simulated yet representative of realistic use conditions where patients with no prior training or use of TOBI® Podhaler™ will be asked to inhale the contents of placebo capsules through the Podhaler device. Due to the use of placebo capsules, the study is considered an interventional clinical study and will be conducted accordingly. The study is an open label, un-blinded, non-randomized study which consists of one visit.