Suppressors are only Federally legal with a tax stamp, typically acquired with a “Form 1” self manufacture or a Form 4” transfer (purchase) along with a $200 tax for the stamp, per item.
The seller would need special ATF licensure and follow an onerous process to sell what is typically considered safety equipment in Europe, ironically. This involves submitting fingerprints, passport photos, and a lengthy (9+ month) approval process on the part of the ATF.
For the self-manufacture, this has been de-factor outlawed by the current regime with DIY kits being arbitrarily reclassified as suppressors themselves. Most if not all Form 1 builds are outright denied.
So, in short, Temu cannot sell these at all. Of course they also occasionally sell selector switches to concert Glock handguns to fully automatic. This is even more comically illegal than a suppressor workaround.
