Unique vs. not unique

There are six items. There are two books, one called "Persepolis", the other is called "Jerusalem". Other four items are Logitech, long eye in supy, which is a can food, type writer ribbon and Trojan horse. They are in different colors and shapes. However, five of them are related to each other and one of them is not. From the material, color and shape, I can determine with one is the exception.
First, let me start from the material. Two books are having a hard and smooth cover and they are made by papers. The Logitech is made up of plastic and it is hard. The long eye, which is a can food…