Please kindly noted that this item is sold by zhongxinda from Joybuy marketplace.[Product parameters] Material: plastic Packing: OPP bag Specification: small: 12*12*6.5 CM medium 15.5*15.5*8CM large 18.5*18.5*8 CM Weight: small 115 grams medium 150 grams large 210 grams [Features] 1. The product has three sizes 12cm 14cm and 17.5cm wide. It is suitable for hamsters hedgehogs or other small pets. 2. An ideal hamster runner can encourage them to practice and maintain their health enrich their night activities and let them enjoy endless running time. 3.Wide Running track brings a relax back feeling as they do not need to bend their back when running. 4. There is a buckle behind the running wheel which can be easily installed on any cage. 5. It is made of acrylic material which is easier to clean than wood material. Please wipe it with a clean damp cloth when necessary.