Review (2/5): Caused stiff, cracking jaw
I originally was attracted to the thought of tightening my jaw muscles/chin area. However, after using for a couple days my jaw was cracking/sore. I would be hesitant to use this type of jaw exerciser. It is easy to clean. It may have been a bit large for my small mouth. But it was a pretty stiff silicone which required a good amount of force to compress.