Quantum Invisible Back Posture

Quantum Invisible Back Posture instantly improves posture. Improves breathing and Straightens your back. Designed to: -Pull shoulders back and straighten spine -Correct poor posture -Fit easily under any clothing -be comfortable, easy to wear and adjustable -be for Men and Women! Medium fits a Shoulder measurement of 16-17.5 inches Large fits a Shoulder measurement of 16.5-18.5inches If you are between sizes, then go up a size