How does the Breather differ from a threshold device?

How does the Breather differ from a threshold device?

Threshold devices are dominating the scientific literature and the market, while resistive devices were initially lacking clinical evidence.
However, clinical evidence for resistive devices is accumulating now, and head-to-head comparisons are available.
According to these, both methods evidently strengthen the respiratory muscles, alleviate dyspnea, and improve exercise capacity.

However, resistive RMT such as using the Breather, has proven superior to threshold RMT with regards to health-related quality of life, exercise performance and aerobic fitness, improving the maximum oxygen uptake (VO2max).