Four months after U.S. regulators tried to block imports of Elf Bar, the top-selling Chinese disposable e-cigarette remains widely available thanks to a simple but effective tactic: changing its name.

Convenience stores in Washington D.C., Philadelphia, New York and other cities remain fully stocked with the brightly colored vapes, sold in fruity flavors like strawberry melon and claiming to contain 5,000 “puffs” per device.

The Food and Drug Administration considers the products illegal. In May, it directed customs officials to seize incoming shipments of Elf Bar and EBDesign, two of the company’s U.S. brand names.

The newer vaping devices bear a different name, EBCreate, and list different Chinese manufacturers than those targeted by the FDA.

The makeover underscores the FDA’s inability to stanch the flow of unauthorized e-cigarettes into the U.S., mainly through large shipping hubs like Los Angeles and Houston.

“E-cigarette manufacturers have proven themselves to not operate in good faith,” said Desmond Jenson, an attorney at the Public Health Law Center. “Until there’s something global that’s a deterrent to selling illegal products this is going to be the status quo.”

Jenson’s group and others have urged the FDA to require unique identification codes on all FDA-regulated tobacco products, which would allow customs to spot and seize illegal e-cigarettes. But the FDA has never proposed such a system, despite receiving the authority from Congress nearly 15 years ago.

FDA’s tobacco director, Brian King, said the agency is monitoring instances where companies try to avoid detection by changing their branding.

“The public and importers of e-cigarettes should be aware that the FDA has a variety of tools at our disposal to take action against these tactics,” King said in a statement. He noted the agency can, and does, add new brands and product types to its import alerts.

The Associated Press reported in June that the number of unique e-cigarettes on the market has tripled to over 9,000 since 2020, a surge driven almost entirely by Chinese-manufactured disposables. Most come in candy and fruit flavors that have made them the favorite tobacco product among teens.

Elf Bar generated U.S. sales of over $271 million in the past year, according to retail data tracker Nielsen. Separate data previously obtained by the AP shows the brand hit U.S. stores in November 2021, racking up hundreds of millions in sales over 18 months before being targeted by FDA regulators.

Public records demonstrate how quickly Elf Bar was able to rebrand itself when the FDA announced its import ban in May.

Two weeks later, a request to trademark EBCreate was filed with the U.S. Patent and Trademark Office. The filing was made by the same patent attorney who submitted Elf Bar’s previous applications. But unlike those filings, the paperwork doesn’t mention Elf Bar’s parent company, iMiracle Shenzhen Technology.