Measure from the centerline of your face at your mouth to at least 1 inch (2.5 cm) past the outside corner of your mouth (you might want to ask a friend to assist you).
The outer edge of the Training Mask should sit against your face at 1 to 1.5 inches (2.5 to 3.8 cm) outside the corner of your mouth.
Double the measurement you have taken and match to the best fit from the below:
- Large: 5 inches (12.7 cm)
- Medium: 4.5 inches (11.4 cm)
- Small: 4 inches (10.2 cm)