Apple's iPhone 6S and the iPhone 6S Plus are highly expected to be announced at the Bill Graham auditorium at San Francisco on Sept. 9. The new iPhones will be thicker than last year’s iPhone 6 models and are expected to come with major improvements to the rear and front cameras.

According to Mac Rumors, the leaked photos of the upcoming the iPhone 6S suggest that the thickness of the device will be 7.08 mm. The iPhone 6 from 2014 sports a slimmer profile of 6.9 mm. The report also confirms the previous speculations claiming that the newer iPhones will be thicker by 0.2 mm than the iPhones from 2014.

The thickness of the iPhone 6S Plus is expected to be 7.3 mm whereas the iPhone 6 Plus has a thinner profile of 7.1 mm. The latest details also reveal that the iPhone 6S measures 138.19 mm in length and 67.88 mm in width.

According to another report from Mac Rumors that cites information from KGI Securities analyst Ming-Chi Kuo, the iPhone 6S will be available in storage variants like 16 GB, 64 GB and 128 GB.

The iPhone 6 and the iPhone 6 Plus both feature 1.2-megapixel front-facing cameras and 8-megapixel rear cameras. However, the upcoming iPhone 6S models are set to arrive with 5-megapixel selfie cameras.

In addition, the front cameras on the iPhone 6S and the iPhone 6S Plus will be upgraded to 12-megapixel along with support for video recording at 4K resolution.

Other improvements that are likely to be available on the upcoming iPhones include Force Touch enabled displays, Apple A9 chipsets, 2 GB of RAM, an upgraded Touch ID sensor and a new color variant of rose gold. The 16 GB, 32 GB and 128 GB variants of the iPhone 6S are expected to be priced at $299, $399 and $499, respectively.

Rumors are rife that a new Apple TV, a 12.9-inch Apple iPad Pro, a iPad Mini 4 and band color options for the Apple Watch could also be announced on the Sept. 9 event.