Apple’s new so-called iPhone 6S may manage to avoid the kind of bending controversy its predecessor incited last year. That’s in part due to a thicker, stronger design, according to a video published by Lewis Hilsenteger, the man behind YouTube channel “Unbox Therapy.”

In the clip, Hilsenteger put the shell of an iPhone 6 against what appears to be the shell of the unannounced iPhone 6S. He doesn’t subject the new shell to a bend test -- he already did that with the iPhone 6 Plus last year at the height of what was informally called “bendgate.” Instead, his video focuses on the subtle changes made to the design.

At first glance, both shells look fairly similar. But upon closer inspection, Hilsenteger noted that the iPhone 6S back case is thicker in all respects. On the outside, he measured the iPhone 6S case at 138.26mm x 67.16mm, a marginal increase from the iPhone 6, with 138.09mm x 66.91mm. The biggest difference comes in the thickness of the sidewall around the volume buttons -- the area of the iPhone where some owners discovered a bend. At that point the iPhone 6S case measured in at 1.9mm, almost twice as thick as the iPhone 6’s 1.14mm sidewall.

Despite the gains in thickness, the rear case of the iPhone 6S comes in at a weight of 25g, two grams lighter than the iPhone 6 case. It's one possible explanation for the use of a different material for the case -- such as the 7000 series aluminum employed in Apple Watch's Sport collection. Alternatively, a patent application published in May has also pointed to Apple experimenting with the use of carbon fiber to reinforce the rear shell and even cases that bend on purpose.

Apple is expected to unveil the iPhone 6S on Sept. 9, along with new iPads and a revamped Apple TV.