Wednesday was a big day for Sony as they released the Sony Xperia Z5 Premium which is said to be the first smartphone with the 4K ultra high-definition display, along with two other Z5 phones.

Engadget said the company launched "a trio of flagship phones" -- Z5 Premium, Z5 and the Z5 Compact during the IFA 2015 in Berlin, Germany.

"The trio shares many attributes, but thanks to one spec, the Premium is by far the most interesting," added the same report.

With an 806-ppi display, the Z5 Premium is sure to be a sought-after phone for Sony fans though the Z5 will reportedly come with a 5.2-inch 1080p display and the Z5 Compact having a 4.6-inch 720p display.

"See every detail with more pixels per inch. That's around 10x the pixels of a Full HD TV, and more than double for most smartphones," read the Z5 Premium's description on the Sony Mobile website.

Meanwhile, CNET said that all the released Z5 phones are equipped with a 23-megapixel camera, waterproof body and fingerprint scanner.

As for its other specifications, Engadget said that the all three phones share almost the same features. They are reportedly powered by a Qualcomm Snapdragon 810 processor, up to 32GB internal storage and a battery which can last for two days.

"Watch more films, listen to more music, carry on chatting and stay out without a care. When you do need topping up, Xperia Z5 Premium can be used together with our Quick Charger for hours of power in just 10 minutes," added Sony Mobile.

But the battery capacity also differ per phone as the Premium will have a 3,430mAh battery, the Z5 with a 2,900mAh and the Z5 Compact a 2,700mAh.

Another differentiating factor among the devices is their RAM with the Premium and Z5 sporting a 3GB RAM while the Z5 Compact only has 2GB.

According to a Sony blog, the phones will have an integrated fingerprint sensor power button "intuitive unlock."

"[The] sensor power button means each device is personal, protected and easily unlockable with a simple pick up and press in one natural movement," added the Sony blog. The phones are also waterproof and dustproof.

As for the colors, Sony Mobile said the Z5 Premium will be available in chrome, black and gold colours with a mirror effect on its back.

The Sony blog added that the Z5 and Z5 Compact will be released globally starting this October while the Xperia Z5 Premium starting November.

There is still no definite price for the devices, but The BitBag noted that the Z5 could start selling at around $400.