This is the first time I’ve owned a device like this, so I didn’t really know what to expect, and it really can’t be adequately explained in the company literature. The “fitting” process is important, but hard to describe. I followed the directions as well as I could, and the result was just passable. Because the gel sets up permanently once the process is complete, you end up with a prosthetic that matches your teeth and gums, but feels very tight and foreign. When I put my mouth guard in place, it’s temporarily uncomfortable. However, within a minute, it feels better. The design keeps my mouth and tongue in the right position, and I can even doze off to sleep wearing it. I’ve had it long enough to feel that it is a good investment for me, and I now carry it with me, just in case I need it.