👉 3 HARDNESS LEVELS - Beginner, Advanced and Expert are our 3 different hardness levels of the Jawliner 2.0. If you don't have any experience training your jaw muscles...then start with the Beginner. If you've already trained your jaw once or twice, then you're on the right track with the Advanced. If you are a pro and have already bitten through all the jaw trainers, then the Expert is the right choice 🦷 JAWLINER offers you the flexibility to use so you can use it according to your time…