This useful bag has been designed to specifically hold an 18" x 24" cutting mat and several quilter's rulers. With all of these tools kept in the same place, it makes getting ready for class that much easier. All pockets are external, with a long pocket for long rulers and two smaller pockets on the front and a large square pocket on the back for different sized rulers. However, it is easier to customize the size of these pockets to suit the sizes of your rulers. The bag has two sets of handles- a short set and a longer set for use over your shoulder.