That whole “that’s not a knife, now this is a knife” line from Crocodile Dundee is about to be useful in the world of smartphones, as Sony shows off a new smartphone that sits at a whopping 6.4 inches, and truly makes you question if it’s a phone, a tablet, or both.

Announced at Mobile Asia Expo in Shanghai, the Sony Xperia Z is a new smartphone-tablet hybrid – commonly called a “phablet” – that aims to deliver much of what the company’s already talked about Xperia Z smartphone does, only in a much bigger size.

“The Xperia Z Ultra is the most exciting revolution in large-screen smartphone entertainment devices with both the slimmest and largest Full HD smartphone display in the world that is second to none,” said Calum MacDougall, Director of Xperia Marketing at Sony Mobile Communications.

Sony’s first device in the growing phablet area, the Xperia Z Ultra packs in a 6.4 inch Full HD display in the minimalistic rectangular look the company sports on both the Xperia Z and Tablet Z devices, with some of the Triluminos technology seen on both BRAVIA TVs and Sony’s VAIO Pro laptops, effectively providing strong colour gamut on the new displays.

The handset is also among the world’s thinnest, with a body measuring 6.5mm thin, but still weighing 212 grams. It is technically a tablet, so don’t expect the 100-150 gram weight most smartphones come with.

You can expect some of the nifty waterproofing we saw on the Xperia Z, though, and this handset will survive an encounter with water down to 1.5 metres for up to 30 minutes, making it possible to use it as a camera under water, or even watch movies where no one will bother you.