Weight Loss Whistle

Features:
1. Reduce breathing difficulties and increase vital capacity by exercising breathing muscles.
2. Work out in a comfortable armchair every day to increase lung strength.
3. Just use it for about five minutes a day (equal to 30 times "breathing").
4. Small size and compact structure, you can use it anywhere.
5. Can be used by almost anyone, without any side effects.
6. Due to hygiene and safety considerations, this item cannot be returned. 7.
There are three adjustable steps for you to choose: weak, neutral and strong.
specification:

Color: pink, blue