The boxcutter/utility knife may be made by Exacto, but it isn’t an ‘exacto type knife’. You want a model 3201. Blade about the size of the nail on your little finger. Even the blades in the assortment kit 5282 are about the size of a thumbnail for the largest. Frankly, reading the TSA list, I can find a couple of more serviceable items for defense that are completely legal to carry on board.