At Delta’s semi-annual media day this week, the airline confirmed rumors that it’s exploring an international premium economy cabin.

Laying out various plans to multiple media representatives, airline officials confirmed that that these changes are in the pipeline.

The product is scheduled for integration into the airline’s upcoming Airbus A350 aircraft, which is slated to start delivery to Delta in the second quarter of 2017. According to Airways News, the aircraft will replace the 747 and largely operate on transpacific routes.

Delta is the second legacy domestic carrier to announce a premium cabin after similar news broke from American Airlines last year. That carrier confirmed that it would be installing its own premium economy cabin on international routes and released renderings of the proposed design.

Like Delta, though, American also has been coy on further details, including an integration timeline or exact routes on which the product would launch.

With a new class of service entering international service, both Delta and American now need to redesign their booking and mileage experiences to mesh with current systems. A big part of that integration will lie in dealing with how economy passengers upgrade from economy into a premium cabin and whether elite passengers will still be given upgrade access to business or first class.

Once the passenger dynamic is solved, the airlines can look forward to a new segment of revenue still largely untapped in the domestic space. Premium economy has been proven largely profitable, while international carriers such as British, Singapore Air, and Cathay Pacific have been reaping the benefits for years. As U.S. airlines keep domestic seat prices relatively low (and unprofitable), new revenue streams like updated business class and international premium economy are going to continue to expand.

For now, passengers on American and Delta can continue to enjoy upgrades from economy to business and the relative simplicity of two- or three-cabin international service. But once international premium economy gains steady footing with U.S. carriers, pathways towards premium experiences will dramatically change.

Photo Credit: Promotional image of a passenger in Delta's premium economy product. Delta Air Lines