Apple announced the iPhone Duo on Tuesday, a device that unfolds into a slightly larger device and then, at the owner’s discretion, folds back into the original one.

Closed, the outer display measures 5.4 inches. Opened, the inner display measures 7.6 inches. The Institute for Deployable Surfaces notes that both of these are phones.

“The customer is not purchasing either state,” said Institute director Dr. Perpetua Halloway-Nkemdi. “Both states already existed and were available last year. The customer is purchasing the transition between them, which is the only part that is new.”

The hinge contains over a hundred components and what Apple describes as a custom torque profile. Institute researchers observe that this exceeds the moving parts in most household appliances, assembled to a tolerance of microns, so that a rectangle may become a different rectangle and then stop.

Apple describes the closed device as roughly the size of a passport, which the Institute believes to be the first occasion on which a telephone has been measured in documents.

“We anticipate a full range,” Halloway-Nkemdi said. “The tablet the size of an envelope. The laptop the size of a folder. Eventually, a filing cabinet, sold as a home.”

Battery figures were published in three variants: thirty-one hours using the inner display, forty-four using the outer, twenty-four using both. Owners are therefore required to declare, in advance, what sort of person they intend to be that day.

Prices begin at $1,999 and reach $3,199 at two terabytes. The Council on Discretionary Hardware reports that purchasers at this level do not compare prices but instead arrive at a figure privately and defend it later.

A protocol already governs the category. Institute research finds that owners of folding devices do not discuss the fold, decline to acknowledge it when it is raised, and will run a thumb across the screen while explaining that there is nothing to feel.

“This is not denial,” Halloway-Nkemdi said. “It is manners.”

One attendee, asked what he intended to do with the larger screen, said he read on it. Asked what he reads, he said: “Emails, mostly.”

Pre-orders open on 16 October, with shipping from 23 October in seventy countries. The Institute expects the first six weeks of ownership to consist principally of opening and closing the device in front of people who have not asked.