The exchange process at Sierra is so simple. They will ship out the new size before they get the wrong size back. This jacket was for my son and we were able to find the exact jacket at a local store so he was able to try it on for size. We had originally ordered the 2XL but it was way too big. He tried on the XL and it fit fine.
Yes you can exchange any item Our return and exchange policy can be viewed here: http://www.sierratradingpost.com/lp2/exchange-return/