Two stars because it does help your posture somewhat while wearingbutholy cow is this uncomfortable under your armsno way in earth i could wear this directly against my armpits and can only wear half an hour tops on top of clothing before having to rip out because of the pain it causesnot sure it is worth it at all its awesome back support i wear it when i work out and help my back straight helps to prevent hurting when i sit down all day to work