I almost left the poshmark description because it thought this was a kids shirt and it was kind of adorable! But it was misleading as it is an adult small. Official BI merch from their webstore, ADULT size small. It’s simply too small for me now. I’m 5’6” and when I weighed 135 this fit great. Not so much now that I’ve gained 20 lbs. This shirt is rad, if you know you know. Just buy it already you totally want to and deserve it!