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

Good

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

Exactly what i was after.

This really makes a huge difference in your stamina I'll put this on and just go for a 30 minute walk and you'll notice the difference in your endurance real quick...

Mask is Dope and My Workouts be Epic... The Only Reason why I gave It Four Stars is because It Slips down My Face as I am Running or Working Out... Overall, Great Purchase for Me...