Strong jaw
I've had these for a couple of weeks now and will tell you that they definitely work the muscles on your face/jaw. The blue one I got use to fairly quickly, although my jaw felt it every time I used it. I'm currently on the red one. Its intense and I can only use it for a few reps at a time. I've used the black one, the strongest one and had to go back to the red/40, it was hard. My jaw feels Stronger, but can't tell if it has done anything for my jaw line as I have a thick beard. When it gets warmer and I trim my beard I'll update this review with results
Rating: 5 stars