iPhone Duo build: 10-layer foldable display, 5.2 mm open, 254 g
Apple’s Duo inner display is a 10-layer stack with nano-texture polymer, glass, titanium plate, and glide adhesives. Unfolded it’s 5.2 mm (thinnest iPhone); folded 11.3 mm and 254 g — Apple’s heaviest iPhone yet.
Beyond the hands-on crease impressions, Apple and MacRumors have filled in the build math for iPhone Duo: a 10-layer inner display stack, plus the open/closed thickness and weight numbers buyers keep asking about.
Inside the folding screen
MacRumors summarized Apple’s description of the inner display:
- 10 ultrathin layers in total
- A nano-textured polymer cover Apple says is up to 40% stiffer than “other materials used in the industry”
- High-strength glass above and below the folding panel
- A titanium plate at the bottom of the stack
- Custom adhesives that let layers “glide past one another like the pages of a book,” relieving bend stress
- A scratch-resistant coating over the nano-texture finish (aimed at glare reduction and minimizing crease visibility)
The outer display uses Ceramic Shield 2 (like iPhone 18 Pro); the back uses Ceramic Shield. The inner foldable surface uses the custom polymer cover instead of Ceramic Shield. Both displays support ProMotion, Always-On, and True Tone, with 3,000 nits peak outdoor brightness, per that report.
Apple’s Newsroom frames the same durability story: premium nano-texture finish, optically clear adhesives, and a hinge designed for long-lasting reliability. Apple still does not publish a fold-cycle rating.
Thickness and weight
Separately, MacRumors logged Apple’s dimensional claims:
- 5.2 mm thick when unfolded — Apple’s “thinnest iPhone ever,” 0.4 mm thinner than the 5.6 mm iPhone Air (and a touch thicker than the 5.1 mm 13-inch iPad Pro)
- 11.3 mm thick when folded (vs 8.75 mm for iPhone 17/18 Pro Max)
- 254 g — Apple’s heaviest iPhone to date (5 g more than the 249 g iPhone 18 Pro Max)
- Displays: 7.6-inch inner / 5.4-inch outer in a short, wide layout
Pre-event rumors of a ~4.5 mm unfolded profile did not land; 5.2 mm is the confirmed open figure.
How this fits the rest of the story
For crease feel in early media hands-on, see our MacRumors crease report. For pricing and ship dates: announce and storage ladder — pre-orders October 16, availability October 23.
Sources: MacRumors folding-screen layers, MacRumors thinnest/weight, and Apple Newsroom.