High Altitude Mask, Training Workout Mask Men to Improve Lung Capacity, 24 Level Breathing Resistance Fitness Mask to Upgrade Endurance, for All Sport: Running, Cardio, Cycling, Gym, HIIT

Works great just what I expected. It makes for a tough workout but that’s the point really. it comes with extra filters and valves to adjust your difficulty. Right size fits comfortably. Low cost. I felt my breathing was improved during my workout. it help increase lung capacity and makes lungs to work hard getting the oxygen. It is perfect mask for people who loves workout.

Good

Exactly what i was after.

I am absolutely amazed this thing is comfortable, and I think it has helped in my goal of doing altitude training. I'm still using the lowest setting with brief excursions into a middle setting. My oxygen saturation will go from around 98% to about 96% with mild activity which is significant for a device that is not directly changing O2 percentages

This mask is great for boosting your training intensity. It made me feel like I couldn’t breathe after only one minute of running in it, so it definitely does the job! The only issue with it I had was the mask kept sliding down my nose and I had to keep pushing it up during my run.