The teaser with the numbers 4, 5 and 6 has manifested into a trio of Intel Atom-powered devices with screens of exactly those sizes. They belong to the new Asus Zenfone line and all run Android 4.3 Jelly Bean (updateable to 4.4) with a new interface customization called ZenUI (what else?). Also, all three Zenfones offer dual-SIM functionality.
The Asus Zenfone 5 features a 5" IPS LCD screen with 720p resolution. Its capacitive sensor can be used with gloves and even use regular pens as a stylus. The phone is powered by a dual-core Intel Atom Z2580 clocked at 2.0GHz and there's 1GB of RAM.
It packs an 8MP "PixelMaster" camera with f/2.0 aperture, which promises great low-light shots. Asus' custom camera can also shoot spherical panoramas (PanoSpheres).
On the connectivity side there's dual-SIM (two microSIM cards), 3G with DC-HSPA+ (42Mbps down, 5.76Mbps up), Wi-Fi b/g/n, Wi-Fi Direct, Bluetooth 4.0 and a microUSB. There's 4GB of built-in storage with a microSD card expansion slot.
The Asus Zenfone 5 packs a sealed 2,050mAh Li-Po battery. The phone measures 148.2 x 72.8 x 10.3mm and weighs 140g. Color options are Black, White Red, Blue and Gold.
The Asus Zenfone 6 is a 6" phablet version of the Zenfone 5 with some enhancements. The glove and pen touch support of the screen are still enabled, the resolution stayed the same too, 720p.
The Zenfone 6 uses the same Z2580 chipset, but some models will have 2GB RAM (others 1GB) and the storage is either 8GB or 16GB (again, depending on the model and with a microSD card slot).
The camera has also been bumped up to 13MP f/2.0 with the same PixelMaster tech. This one includes SonicMaster audio tech too. The battery has grown (to 3,240mAh capacity) and so has the device itself (166.9 x 84.3 x 9.9mm, 200g).
The connectivity options are the same right down to the dual-SIM functionality. Color options are a tad more limited: Black, White, Red and Gold.
The Asus Zenfone 4 is the compact device and the runt of the litter. With its 4" screen it only measures 124.4 x 61.4 x 11.2mm and weighs 115g.
The screen resolution has been dropped to WVGA and instead of IPS you get old TN TFT (viewing angles on this are certainly questionable). The chipset has been demoted to a dual-core Intel Atom Z2520 (clocked at 1.2GHz) with 1GB of RAM.
The camera is a 5MP shooter, but more worryingly the battery has a measly 1,170mAh capacity. At least this one is removeable so you can carry a spare if needed. Connectivity features are exactly the same as on the others and the color include Blue among the other options.