Wardrobe/costume piece used in the production of Netflix's "Cobra Kai" series.  There is a tag inside the shirt from the costume department, which says it was worn by Miguel Diaz's stunt double (Noah Bain Garret) in episode 103 ("Esqueleto").  The tag also says this shirt was used for scenes in the Cobra Kai dojo (being a stunt shirt it is likely from an action scene of Miguel training with Johnny).