They fit the “NEW iPhone 6.1” and “NEW iPhone 6.5” models of the 2018 model line. The manufacturer was obviously afraid to name the device, so he used abstract names.
Considering that the sizes of the accessories manufacturer for Apple products have been known for a long time, making covers was not difficult.
Speck itself produces covers since 2001, and its main office is located in the very center of Silicon Valley. Who knows, maybe Apple handed them the blueprints through the fence of the new campus.
On the Speck website itself there are no covers for the iPhone XI, Xs, Xs Plus and other variations of the alleged names of the new Apple smartphones. For them, only stubs have been created without any description. [Reddit]