One preemptive "stay the hell away from protech" here.
Their site is offline for now, but if it comes back up do not order from them. They's be rippin fools off left and right.

Personally I've used shock dr, everlast and opro, and I like the double shock dr the best. Mouthguards are kind of like holsters; you'll go through a few until you find the one that works best for you. Unfortunately moughtguards do not have the same resale value.