This trial sheet is to purchased if you are uncertain of your nail sizes. Also if your nail sizes DO NOT fit any of the set sizes (X-Small through Large) you are considered custom. If custom is available for a particular set, you will need to list your nail sizes based on this chart at checkout. Set Sizes come as follows: Large: 0/4/3/5/7Medium: 1/5/4/6/8Small: 2/5/4/6/9X-Small:3/6/5/7/9