The SISU mouthguard: an astonishingly thin, obnoxiously bright, boomerang-shaped hunk of technology — revolutionizing mouthguards across the universe by offering more protection and less mouthguard. Youth or adult, braces or not, for high-impact sports or a pick-up game in the backyard — our complete line of high-tech SISU guards are the ultimate athletic mouth shields you once thought too good to be true.