Nikkei Asian Review is adding to recent reports that Apple will move to an all-glass design with the iPhone 8 next year, while reporting that the lineup will add a 5-inch model. Apple previously used an all-glass design with the iPhone 4 and iPhone 4s, but switched to aluminum backs with the iPhone 5 through iPhone 7. And a 5-inch iPhone 8 would add a new option to the current lineup which includes 4.7-inch and 5.5-inch flagship models.

“Apple has tentatively decided that all the 5.5-inch, 5-inch and 4.7-inch models will have glass backs, departing from metal casings adopted by current iPhones, and Biel and Lens are likely to be providing all the glass backs for the new iPhones next year,” the source said.

Last month, KGI separately advised that the 2017 iPhone design would shift to an all-glass design as well. The idea is that the high-gloss Jet Black finish introduced with the iPhone 7 is highly popular but difficult to manufacture and prone to scratching. While glass may be known to shatter on impact, the surface holds up much better to scratching.

The all-glass front and back is expected to be combined with a metal casing around the edges similar to the iPhone 4 design. KGI has forecasted that high-end models could use stainless steel metal while lower end models rely on aluminum. The all-glass iPhones coming next year are also widely expected to adopt AMOLED displays.

While Nikkei reports that the iPhone 8 will be offered in 4.7-, 5-, and 5.5-inch versions, previous reports have pointed to the possibility of a 5.8-inch version. Also up for debate is whether or not the 2017 iPhone will introduce a curved display: KGI appears to think not while Nikkei expects the 5.5-inch iPhone to go curved.

At the time of the curved display report, Nikkei also mentioned the possibility of a larger iPhone model, however, while the latest report settles on 4.7-, 5-, and 5.5-inches for now.

Nikkei’s reporting today advises that plans could change between now and the iPhone 8’s launch next year.