Apple Inc. is maintaining utmost secrecy about its upcoming device, dubbed as iPhone 6s. But several details, including release date, features and design have leaked over the last few days. A report has claimed that the device will be much stronger than iPhone 6.

According to a video by Lewis Hilsenteger of Unbox Therapy (via Business Insider), who claimed to have tested Apple's upcoming phone, durable material found in the Apple Watch Sport is used in the new device too, which means it will be stronger than iPhone 6. In fact, the device can bend if the video demonstration is to be believed.

Hilsenteger discovered that iPhone 6s contains more zinc than iPhone 6, making him conclude that it is the same material used in Apple Watch Sport, which is 60 percent stronger than the current flagship smartphone. iPhone 6 bent low when applied 30 pounds of pressure but the upcoming device bent only slightly despite putting 80 pounds of pressure.

However, it seems the looks of iPhone 6s will be very similar to its predecessor.

The Cupertino-based giant is expected to release its upcoming device in September. Forbes has reported citing claims by Japanese site ITHome and German website Macerkopf that iPhone 6s and iPhone 6s Plus will be launched on 18 September. M.I.C. Gadget also reported that it will be announced on 11 September and launched on 18, while Telegraph and Mobile News claimed that it will be available for pre-orders on 18 September and hit the stores on 25.

According to reports that have surfaced so far, iPhone 6s is expected to sport a 4.7-inch display, powered by a A9 chip processor, and runs on iOS 9. It is also expected to come packed with 32 GB internal memory, 2 GB RAM, 12 MP camera, improved fingerprint censor, Force Touch and stronger aluminium alloy chassis.