The "operation" is very simple: add about 70 ° warm water and replace after about 1min in the mouth, so that the then soft rubber to adjust to the shape of the jaw. Then with cold water "scare".
Why I gave only 1 star? Well, in the first "fitting" to press the teeth of the lower jaw in the plastic. As long as the rubber is soft, which goes smoothly. But during cooling, the whole track seems to somehow forgiven, that is what still fit in the warm state, no longer fits in the cooled state as 100%. By the material molded teeth marks, the pine tries in his sleep again occupy this position at the latest. And that makes at least for me for the jaw will exactly take the position at night "gnashing of teeth" at the latest, which has pushed the teeth in the form of footprints into the material. The lower jaw Specifically pushed back slightly, resulting in the end to the same problems, which is why I bought the track at all: jaw pain.