The iPhone 7 could be the thinnest iPhone ever.

Ming-Chi Kuo of KGI Securities says the phone could be between 6 and 6.5mm thick, according to Tech Radar. By comparison, the Samsung Galaxy S6 is 6.8mm thick.

However, to make the device so thin, Apple might have to make a major change to one of the ports on the phone. In the iPhone 7, the company might be removing the traditional 3.5mm headphone jack and replacing it with a different port. This would prevent customers from using any normal pair of headphones, requiring owners to instead purchase headphones that were either Bluetooth enabled or compatible with the new jack that Apple chooses to use.

Meanwhile, as Apple trims down the next iPhone's thickness, the battery life could suffer.

Another way to keep the iPhone 7 thin is by using a different internal chip. Apple might rely solely on TSMC to make their chips. For the iPhone 6s, Samsung made between 60 and 70 percent of the chips, while TSMC made the remainder. For the iPhone 7, Apple could ditch Samsung completely as a chipmaker. TSMC's production strategies yield chips that require less space.

Apple is due for a screen improvement with the iPhone 7 as well. This probably means that the screen will be 1080p for the first time in an iPhone. The size of the screen will likely be the same, 4.7 inches on the iPhone 7 and 5.5 inches on the iPhone 7s.

3D Touch, the pressure-sensitive technology that was introduced on the iPhone 6s, will almost definitely return on the iPhone 7 and it could get some small improvements too.

The chip used in the iPhone 7 will be the A10 processor. This processor will be faster than the A9 processor, but the practical improvement is still unknown.

Apple usually releases iPhones every September, and that is expected again in 2016. The price of the iPhone 7 will probably be $650 to start, just like the iPhone 6s.