There are lots of confusing rumors running around about Microsoft’s upcoming lineup of Lumia smartphones. While we do know for sure that there will be two flagship smartphones announced this fall, their hardware specifications have yet to be confirmed.

Many sources claim they have the correct list of specs packed inside these high-end devices, but there's no way to tell which ones are more accurate.

While sources claim Microsoft does not plan to launch any high-end devices made of metal, instead the company will focus on the material used until now: polycarbonate.

However, it looks like there's another rumor coming from Germany via WindowsUnited, which says one of the Lumia flagship smartphones will be made of polycarbonate.

The smartphone will pack a Qualcomm Snapdragon 810 processor, iris scanning technology, on-screen navigation buttons and USB Type-C port.

The device will be compatible with Continuum for Phones via a docking adapter 3x for USB, HDMI and USB Type-C, which will be available for purchase separately early next year. Design-wise, this handset will look very much like the Lumia 640.

The polycarbonate-made flagship smartphone will be announced along with Windows 10 Mobile this fall, and will certainly hit shelves by the end of the year.

Polycarbonate or aluminum? Which one do you prefer?

The second high-end Lumia smartphone to be announced by Microsoft will be made of aluminum and it is likely to be powered by Intel's SoFIA chipset, which has been rumored to be adopted by Microsoft inside its Windows Phones.

This flagship aluminum smartphone will be more expensive than the iPhone 6 and Samsung Galaxy S6 and is likely to be part of a new lineup of Windows Phones.

It won't be surprising if Microsoft will launch this aluminum-made smartphone as “Surface Phone.”

However, it appears that this handset will be announced a few months later, which puts its unveiling date sometime in early 2016.

I'm personally hoping they will release a budget or mid-priced phone with USB type-c, with at least a 5 MP camera and 16 gigs of memory. That will make me happy.

So... What is polycarbonate anyway?