- The A1 focuses on establishing nasal breathing and myofunctional habit correction. It is soft and flexible, which gives the best compliance, while adapting to any arch form and malocclusion. - It has small breathing holes to establish continuous nasal breathing and myofunctional features to promote correct habits. - Only move to the A2 when the A1 is staying in overnight and nasal breathing has been established. **For further product information, please contact Chat Support**