NOGALES, Ariz. (KLAS) — A tractor-trailer heading across the southern border was carrying necklaces made in China that promised to create anti-viral clouds to prevent against COVID-19, officials said Thursday.

The truck, which was going through the Nogales, Arizona, border station from the United States to Mexico was carrying 30,000 so-called “Virus Shut Out” devices, officials with Customs and Border Protection and Homeland Security said.

Though the incident happened April 16, it was first reported Thursday.

The necklaces, which border agents described as looking like a lanyard with a blue packet on them, contained chlorine dioxide, which can cause severe breathing problems.

‘Virus Shut Out’ necklaces (CBP/KLAS)

In all, the truck was carrying 30,000 of the phony devices with a value of half-a-million dollars.

The packaging lists several cautionary statements, the first, being to not put the item “in your underwear.”

“In addition to posing potential health and safety hazards, counterfeit goods are often of inferior quality,” agents wrote in a news release. “Peeling labels, low-quality ink or printing errors on the packaging, and loosely packed items in the box can be signs that the product you purchased may not be legitimate.”

‘Virus Shut Out’ necklaces (CBP/KLAS)

Border patrol recommends purchasing items through authorized retails and “if the price of a product seems too good to be true, it probably is.

Counterfeits can be reported online or by calling 800-BE-ALERT.