Material: PlasticColor: Sent randomInner diameter:10 cm/3.9inchBracket: 12 x 7 x 13 cm/4.68x2.73x5.07inchFeatures :Brand new and high qualityIt is excise wheel with bracket that won't emit any voiceRound corner design to prevent accidental injuryMade in high quality material， beautiful and exquisiteDivided entrance design to prevent hamster flying out of itNo need to worry hamster's potential safety hazardFits for hamster， guinea pig， chinchilla etc.