POWERED BY DIFFUSIX‰ã¢ TECHNOLOGY A SMALL BUT MIGHTY MOUTHGUARD FOR SMALL BUT MIGHTY MOUTHS SISU Junior is our youth mouthguard designed specifically for kids ages 7-10. With its quick, custom fit and improved protection, SISU Junior allows your pro-athletes-in-the-making to little-league more safely than ever before. AND because it‰۪s so comfortable, your kids won‰۪t entirely hate you for making them wear a mouthguard! Everyone wins.