A fun tunnel for your small animal, and they help fulfill your pets' natural chewing and burrowing instincts. Plus, every tube includes free bedding material. Encourages natural burrowing and chewing instincts. A perfect place for your cozy critters to hide-out Encourages natural burrowing and chewing instincts Comes in blue and red! Sizes: Small 6"Long 2.5"Diameter : For mice, small hamsters, and gerbils. Medium 9"Long 4"Diameter : For hamsters, rats, sugar gliders.