American Airlines' new Flagship Suite business class is set to enter service in June. Here's where you can fly it first.

The craze of offering sliding doors has rippled through the industry. Rivals like JetBlue Airways have upgraded their highest-end cabins to feature the doors, while Santiago, Chile-based Latam Airlines said Thursday that it started operating its new business class with sliding doors on some of its aircraft, part of a $360 million fleet refresh.

Set to debut on select flights from Philadelphia, American's Flagship Suite seats include privacy doors, personal storage space, a wireless charging pad and a chaise lounge seating option.