It does several things for you.
1. It puts a clear and level finish on your model that will not yellow. That makes it ideal as a base for applying decals. It will not model or blotch like clear laquers can. It also wont orange peel and dries fast.
2. It's great for canopy's in several ways. It corrects minor flaws and protects the plastic. Therefore you can coat your clear plastic, mask it with something like bare metal foil, and remove the mask without worrying about damaging your plastic. Then a final coat to get it a well maintained appearance if you wish.
3. It's easy to apply. No thinning. You can spray it, dip it, or brush it on. It always levels perfectly.
4. Clean up is easy as well. A little alcohol and it comes right off. But you also don't have to worry about it coming off with water.
5. You can shoot a clear flat over it to tone it down. I like Microscale products. But you can put most anything on it I believe. At least anything I've ever used.
6. It's cheap and you'll never run out. At least I haven't.
This is just one of those great finds. I'm certain you'll be very happy with it and you'll probably never use anything else for this application again.
Dave