2.0および3.0用トレーニングマスクヘッドストラップ ブラック

As advertised

I like how you can adjust the strap to your head size for a comfortable fit. Also helps keep mask in place when your doing harsh training such as running, lifting ect.

Works, but the large version of the training mask I bought new had one included.

an absolute must have for a good comfortable fit, its a shame its not just outright included with the training mask.

I honestly loved this product, i don't care if they say that it's useless. I tend to sweat a lot when wearing this and after taking it off i feel that my breathing is getting better. People say it helps make lungs stronger, i've seen many athletes use it. But i read online that it's useless. WHOCARES when you look like a freaking Bane from batman jogging on the treadmill or whatever! You look like a beast!