First of all, I ordered a size larger than I wear just in case it ran a little small.  Still upon wearing one for an hour I feel like someone has taken a band and tied it around my chest as tightly as they can.  It pushes your boobs together as if it were trying to hide them.  Very uncomfortable. It is NOT light and breathable as it says it is.  Gonna pack these up and ship 'em back if it doesn't cost a fortune to return them.  If it does, well, I'm sure they'll make ok slingshots.