MaterialWood, Polyvinyl Chloride Target SpeciesGuinea Pig, Mouse, Gerbil, Chinchilla, Hamster Size: small diameter 13cm/5.1in, Perfect playground for mice, chinchillas, guinea pig, syrian rat, gerbil and dwarf hamster. Safe Wood-plastic Board Material: Our rat wheel is made of quality Wooden board and PVC material, which is durable, eco-friendly, nontoxic and chew-resistant, safe to your pet. Silent and No Noise: Our quiet spinner adopts a stainless steel bearing design, rolling smoothly and silently, so that the hamster will not disturb your rest and sleep during exercise, it brings your little hamster endless running happiness, keep themto exercise for maintaining their strength and well-being. Firm and Non-slip: The hamster exeicise wheel does not fall off, non-slip convex lines design allows your pet to not slip and get hurt while running and playing, safe to use, easy to put into the pet cage. The accessories of the hamster wheel can be fixedin the proper positionand, you can adjust the height of the hamster wheel to fit the species of your small pets. Easy To Install and Clean: The exercise hamster cage attachment comes with instructions and installation tools, is very easy to mount to most cages. The wood-plastic board material can be washed with water and will not fade, you can wipe it with a clothto easily clean. Do not immerse the shaft in water