The Battle Sports Carbon Chrome Oxygen Lip Protector Mouthguard with Strap was developed by athletic, dental and medical experts to deliver superior airflow and better performance to you. With the largest breathing hole on the market, the mouthguard delivers more oxygen to the muscles for faster recovery, clearer thinking and faster reaction times. The mouthguard also does not require boiling, can be used with braces, and helps open TMJ. Delivers more oxygen to the muscles for faster recovery, clearer thinking and faster reaction times. No boiling required, works with braces, helps open TMJ, and offers maximum breathability. Includes an advanced composite and absorbent shield. Mouthguard size is one size fits most. Patented design leverages SCUBA breathing innovations. Largest breathing hole on the market. Developed by athletic, dental and medical experts to deliver superior airflow and better performance.