These are designed for cards of 56 MM X 87 MM, or 2 1/4 X 3 1/2 inches. This sleeve is 40 microns thick and come 100 per pack. These are GREAT for games with a lot of cards that stack. We have play tested a few thicknesses and this thickness works best if you have over about 70 cards in a pile. Any thicker and they simply fall over and difficult to shuffle due to the thickness.