I was skeptical at first, but after using the beginner level for 10 minutes every other day, my jaw feels noticeably stronger. Starting on the red 50 LBS now. Simple and easy to use anywhere.

The best part is I can train while doing other things — working, driving, watching TV. The three resistance levels are a nice touch so you're not stuck on one difficulty.

Silicone feels solid, no weird taste or smell. Took a few days to get used to the chewing motion but now it's part of my routine. Would recommend starting with the blue ones first.