The Mouse Cubby for Thoren is designed specifically for the Thoren Maxi-Miser #9 mouse cage. It fits snugly against the ceiling, floor, and wall to create three separate cubbies that open to a common area. Made of durable corrugated fiberboard, the Mouse Cubby is built as a disposable product that can be chewed into nesting material. This allows mice to creatively adapt and modify their environment, keeping engaged and minimizing aggressive behavior. This is a sample pack of 20 dividers. They are shipped Non-Irradiated.