MaterialPlastic Item DimensionsLxWxH 4.72 x 4.72 x 4.72 inches Made with durable plastic materials.Relieves boredom and increases activity level and giving him a fun spot to play Ideal for hamster or other similar size small animals .Encourage healthy exercise in a secure way Makes a great temporary holding area to keep your furry friend while you clean their home 4.8 inch diameter .Ideal for dwarf hamsters, mice.Fun exercise toy to maintain your pet's alertness and agility.Provides interactive fun for the pet and the pet owner Before put your pet into the plastic ball, ensure you correctly assemble the plastic ball.Assemble the hamster plastic ball : 1.Align the buckle positions of the two hemispheres, buckle up to the correct position, and turn slightly clockwise to lock 2.Whencovering the top cover, pay attention to align the four snap positions , and turn to the right to fix 3.Put your hamster into the plastic ball and watch them play on the flat floor .