I have had a few different products just like this one, the one thing I have found with each different brand is that the underarm area is always too tight. I generally fit into a medium for clothing so I size up and got this as a large as they are generally pretty tight I would say you may need to go up an additional two sizes when ordering this specific one as the large was very difficult to get on.However product does work as described and will make you sweat more than normal.
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