These are almost as necessary as paper towels in our district. The 20 pack makes it easy to keep these on hand. A bit thinner this last time than I am used to but they still stack the same on the goggles.
My 10 year old son has to wear prescription glasses or his contacts so its a must that the goggles stay on. Having the tear-offs allows him the chance of clearing a few times when he doesn't have the options to just pull his goggles off like other riders.