The Small Grassy Roll-A-Nest is an all natural grass hide-out that provides the ideal spot for your pet to play and rest! Each nest is made of natural plant fibers hand-woven onto a sturdy support frame. These natural plant fibers are safe for your pets to graze and chew upon. Offers the perfect snuggling spot for, Hamster, pet rats, Mice and other small sized furry friends. Measures 4" round.