After months of rumors and leaks, Apple is expected to unveil the new iPhone 6 at a massive press event on Tuesday. 

There's already a wealth of prediction and revelation from sources with knowledge of Apple's inner workings, however, in terms of solid information, there's not much that is certain about the company's new flagship smartphone. If rumors are to be believed, the device will come in two variants with larger screens than previous iPhone models.

Apple is said to be rolling out a 4.7-inch model and a 5.5 inch model. The two variants would be larger than the 4-inch iPhone 5 and the 3.5-inch iPhone 4. According to a recent report from Japanese blog Macotakara, the new Apple smartphone will start a new naming convention for the company. The smaller variant is rumored to be called the "iPhone 6" while the larger version may be called the "iPhone 6 Plus." 

It's still not clear whether the two models would be launched at the Sept. 9 event. The production for the larger iPhone 6 was said to have been delayed, and an early 2015 release date started floating around. However, many reports have already predicted simultaneous launches for the two models. If the sizes of the device turn out to be true, it would certainly encroach on rival Samsung's turf. 

Samsung has long cornered the market on phablets. The segment is growing in significance and Apple is the late entrant to the skirmish. The phablet market is mainly a lopsided race between Android and Windows. The segment, which amounted to 20 million units shipped in 2013, is expected to grow to 120 million units by 2018.

However, with Apple expected to release phones with larger screens, Samsung's dominance will soon be challenged. Aside from the screen size, other expected features for the iPhone 6 points to Apple's desire to cut into the market share of its favorite courtroom battle dance partner. The company is looking to attract followers of the Android with near-field communications (NFC) integration. The company is said to be planning a new mobile payment system for the iPhone 6, with support from pharmacy chains CVS and Walgreens. 

Aside from the iPhone 6, Apple is also expected to launch the "iWatch" smartwatch. The device, which was earlier rumored to be released in October, may not ship until early 2015.