This mobile library system is ready to roll with six single-color picture book bins. The sturdy aluminum rack moves easily on the four locking casters, or can be permanently placed with the included stationary feet. Each sleek plastic bin comes with two snap-tight dividers to keep books neat and give you flexible organizing options. You can set up one, two, or three sections per bin. Built-in label holders with protective covers keep labels clean and smudge-free. Rack assembly required. Choose from 12 colors plus clear!