Where can I find the purple Calvin Klein briefs that Marty Mcfly had in Back to the Future?

I dont want any new remakes of the Calvin Klein underwear. I want to know where I can buy the 80s


Calvin Klein's.|||You may not be able to, as certain older clothing is a hard commodity to come by, especially underwear from the 80s.





I mean, I do not know if any retro shop has unopened packages of it