Boil and wear. Comes with clear plastic carrying case. Spot the end in the mouth of yours with the top of teeth. In case the end is just too in length, trim the ends again before it fits perfectly. Boil the water area the end on a spoon as well as dip in a tub filled with warm water for aproximatelly 8 9 secs. Warning: Don't depart the end in case water for a longer time compared to nine seconds or even the design shall be distorted. Quickly insert into mouth. Close tooth with care to assure an uniform bite. Don't hit difficult or perhaps the mouthpiece will be pierced by you. Push the guard into the roof top of the mouth of yours by pressing the tongue of yours on it. Preserve the end in this spot for aproximatelly one minute. Mouthpiece situation not pictured.