my opinion [SEP] it did not work out so well for me though that does not necessarily mean the product will not work out for others if you never wore one before you would think you would just hook it on like a backpack which you kind of do anyway it also includeds a useless piece of paper with instructions on how to put it together except they leave out the most important part amazon also has a video on how to put it together from the manufacturer which is also useless because the most important part that you need to know is only a frame or two as if they knew it was going to be difficult to put together and did not want the viewers to see it i tried it on over my bareback without any undergarment shirts i also tried it on over a t shirt in both cases there was absolutely no signs of correction on my curvature spine the y shape piece in the back rode all the way up to my neck instead of staying in the area of the curvature as far as being comfortable it was okay you just felt the strap coming out from underneath your armpits and over to your shoulder to be velcroed onto the strap you would feel the pressure of the strap against your skin or over your t shirt undergarment top but that is all it was the pressure gives you the illusion as if your back is being straightened out but in reality it did not do not one bit of correction not even a little maybe for my particular curvature my particular curvature may be beyond repair correction i may end up returning it