The maker of Wise potato chips has been sued by two consumers who said it fills bags less than halfway, deceiving them into overpaying.

Wise Foods systematically underfills bags and has left them 58 percent to 75 percent empty, well above the 30 percent that might be justified, Sameline Alce and Desiré Nugent said in a lawsuit filed on Monday night in Manhattan federal court.

Alce, from New York City’s Bronx borough, and Nugent, from Washington, D.C., said they would have paid less for their chips had they known about the empty space or if bags were “proportioned” to their contents, even if the labels showed the correct weights.

Wise, based in Berwick, Pennsylvania, is a unit of Mexico’s Arca Continental SAB. Neither immediately responded on Tuesday to requests for comment.

The proposed class action seeks damages for consumers in New York and Washington, D.C., as well as packaging changes.

The plaintiffs pointed to a 2.75-ounce bag of Wise Ridgies Sour Cream and Onion chips that they said was filled to only 2.5 inches of its 10-inch capacity. They also said PepsiCo Inc’s Frito-Lay division fills its Ruffles potato chip bags higher.

“Even if defendant’s net weight disclosures are accurate, such does not eliminate this basic deception,” the complaint said.

The lawsuit is one of many targeting alleged excess empty space known as “nonfunctional slack-fill.”

According to the U.S. Food and Drug Administration, it is not misleading for companies to leave such space atop packages to protect or ensure the proper sealing of contents, which may also settle during shipping.

In September, a federal judge in San Francisco approved StarKist Co’s $12 million settlement over claims that its tuna cans contained less fish by weight than legally permitted.

The case is Alce et al v Wise Foods Inc, U.S. District Court, Southern District of New York, No. 17-02402.