S: Belly circumference 24.1?- 27.5?(61-70 cm)
M: Belly circumference 27.5?- 31.4?(70-80 cm)
L: Belly circumference 31.4?- 35.4?(80-90 cm)
XL: Belly circumference 35.4?- 39.3?(90-100 cm)
This back braces for lower back pain is full elastic and breathable, which can giving good support to the waist. Moreover, this is a waist trainer, it can help people to loose weight if you wear it in gym.
Note: This back brace is not supported to machine wash. If you want to wash this support belt, just soaking it in water, drying it naturally, wiping it with wet cloth, but not explode.