The ASUS ZS551KL smartphone recently visited Bluetooth SIG and is a candidate to be the upcoming ASUS ZenFone 4 Pro. Leaks and rumors about the new ZenFone 4 lineup have been emerging over recent weeks and the device named the ASUS ZS551KL has passed Bluetooth 5.0 certification from the authority. It's often the case that various smartphone certification filings are spotted just before a device is officially launched, and in late June six ZenFone 4 handsets received Google certification. In a post on the manufacturer's forums these were named as the ASUS ZenFone 4 Selfie, the ASUS ZenFone 4V, ASUS ZenFone 4 Max, ASUS ZenFone 4 Pro, and two different models of the ASUS ZenFone 4.
Following said report, the ZenFone 4 Max (ASUS ZC554KL) was made official earlier this month as the first in the series, and just yesterday a report indicated that further ZenFone 4 variants will launch on August 17, although that is yet to be confirmed by the manufacturer. However, if the report is accurate then it's certainly possible that the ASUS ZS551KL could be the ZenFone 4 Pro, a follow on from the ZenFone 3 Deluxe that launched last year as the ZS550KL. Previous leaks have also suggested that the regular ZenFone 4 will be the ASUS ZE554KL while the ZenFone 4V will be the ASUS V520KL.
Specifications for the other smartphones in the ZenFone 4 lineup have yet to be confirmed, but specs of the aforementioned ZenFone 4 Max include a 1.4GHz Snapdragon 425 or 430 quad-core processor (depending on variant), a 5.5-inch display with Full HD resolution of 1920 x 1080, 13-megapixel dual rear camera arrangement, and an 8-megapixel front-facing shooter. The highlight of the ZenFone 4 Max is a massive 5,000 mAh battery (hence the name), and it comes in several configurations for RAM and internal storage and runs the Android 7.0 Nougat OS skinned with Zen UI 3.0. The device was officially launched with little fanfare in Russia with a price of 13,900 Rubles (around $235) but has limited availability so far. It has a metal unibody build, so it could be the case that others in the ASUS ZenFone 4 range, including the ZenFone 4 Pro, will also have metal designs. Although that remains to be seen, there will likely be further news on the ASUS ZenFone 4 lineup before too much longer.