BIRKENSTOCK T-SHIRT SIZE SMALL BLACK W/ WHITE CHEST & SLEEVE LOGO STAFF ITEM?

Never seen another in my travels. Seems to be printed on a Gildan “Softstyle” tee so I’m not sure if these were made for employees in a retail shoe store, or they had a promotion or an in store demo / person. That’s what I believe this probably is. I don’t think it’s a “bootleg” or inauthentic. I don’t believe it was ever meant for sale to the public or customers. It’s probably a company rep shirt or something along those lines. Probably a pretty rare item for someone who loves and collects BIRKENSTOCK. Their sandals and clogs are the bomb. I wish I could find (and afford) a pair of Stüssy x Birkenstock Boston Clogs ( in butternut or whatever colour tbh ). Anybody out there have a pair? Lol I need a size 45!! The shirt has something spilled on the front which you can see in the pics. I’m gonna delicately launder this in the next day or two to remove it and I’ll retake pics and measurements and such. Just threw it up there for now! Any questions please feel free to message me and I’ll do my best!! :)