Experience effortless, easy fitting with the SISU 3D Custom Fit Youth Mouthguard! SISU Mouthguards are known for their unmatched protection, comfort, cleanliness, and remoldability. Though it may not seem possible, SISU has made an even better mouthguard with this 3D custom fit. This mouthguard improves on previous SISU models and adds a number of new features such as a pre-formed guard and variable material thickness to put protection where it is needed and comfort where desired. Effortless, easy fitting.