The ultimate mid-back pillow will change the way you sit and feel! Current chairs and car seats, even the most high-end, focus exclusively on the lower lumbar. Even worse, they both tend to push the shoulders forward. This can lead to a collapsed mid-back alignment and makes the head tilt forward. Most heads weigh between 8 to 12 pounds - for every inch your head moves off-axis, it gains an additional 10 lbs of gravitational weight. The Astralign pillow provides a gentle amount of forward and upward thrust to the mid-back, which, by doing so, also helps put the neck and lower lumbar in alignment. Proper posture is vital, and using the Astralign, simply by placing your muscles in the right position, can help train you to achieve that.

This is the sizing info:

⭐ Large size is for chest-to-back measurements ranging from 35.5"to 45"
⭐ Medium size is for chest-to-back measurements ranging from 30.5" to 35.5"
⭐ Small size is for chest-to-back measurements ranging from 25" to 30.5"

You want the ‘wings’ to hug your ribs nicely.
As a rule of thumb, Large is for large-body people, Medium is for medium-bodied people, and small is for petite adults and children.
If you have any doubts take a tape measure and drape it around your torso(under the breasts) and around the back.

All sales final.