THIS RETAINER IS ONLY GOOD FOR ABOUT 2O MINUTES OF ITS USE....MY TONGUE IS NOW SORE BECAUSE I HAD IT FOR THE WHOLE DAY AND I HAD TO BECAUSE I DIDN'T WANT MY BOSS TO SEE IT AND I COULDN'T REMOVE IT BECAUSE I DIDN'T WANT MY HOLE TO BLOCK :(, I RECOMMEND THAT THE BAR BE A LITTLE LONGER JUST FOR SOME SOUGHT OF COMFORT...PLZZZ