This book shelf features a clever design that allows you to separate it into two 2-tier shelves, which can be used individually or stacked together to form a 4-tier bookcase; This means you can use it as a desktop bookshelf to keep your favorite books at arm's reach, or as a floor-to-ceiling bookshelf to showcase your entire collection and bring an elegant touch to your room; This is great for those who have limited space, or who like to change their furnit.