Speculations about the Microsoft Lumia 840 only come with one certainty -- the upcoming mid-range device will be a much better version of its successor, the Lumia 830.

There are reports, including Christian Today, saying that the Lumia 830 is being discontinued in some countries such as India, which could mean that a successor for the device is already on its way to replace the Lumia 830.

The news outlet added that "stocks of the Lumia 830 has reportedly been depleted in most India stores and from the looks of it, they will not be replenished."

Listed below are the most notable rumors about the Lumia 840's specifications and features. Note that these are all unconfirmed at the moment and official news from the tech giant is yet to be announced regarding the device.

A 5-Inch Display Size

The Lumia 830 wasn't exactly an overachiever when it came out in the market, but Microsoft isn't abandoning the handset's display size for the Lumia 840. Venture Capital Post claimed that the Lumia 840 will have a 5-inch 720 x 1280 resolution (HD) screen, as well as a quad-core 1.2 GHz Snapdragon 400 CPU and Adreno 305 GPU.

Dual-SIM Support

According to a Microsoft employee who wishes to remain anonymous, the Lumia 840 may pack Dual-SIM support, 13-14 MP rear camera with PureView technology, and 5 MP FFC, adding that "while it is not sure what the name may be, we may call it Lumia 840 for our convenience," Nokia Power User reported.

Upgraded Windows OS

Though some are expecting that the handset will have the Windows 10, the news outlet also noted that the Lumia 840 will be equipped with a pre-installed Windows 8.1 GDR2.

For those wishing to have the Windows 10 in their smartphones, International Business Times noted that the OS could be included in the Lumia 940.

Design Similar to Lumia 830

The Lumia 840's design could be just like the Lumia 830's, International Business Times added. However, it could come in slightly modified and improved features and is expected to use a processor with better performance.

Price and Release Date

Venture Capital Post estimated that the Lumia 840 could be released in October of this year. As for its price, the device is expected to cost above $382 just like the Lumia 830, Chistian Today wrote.

Aside from the Lumia 840, Microsoft is also said to announce other devices from its Lumia slate in the upcoming 3 to 4 months, Nokia Power User noted. This includes the Lumia 435, Lumia 532, Lumia 640, Lumia 640 XL, and Lumia 540.