Prevue Pet Products 6" Quiet wheel 90016 is constructed entirely of plastic with ball bearings that keep the wheel whisper-quiet when in use. No more squeaks or rattles! Great for providing exercise inside or outside of the cage. Use with a stand or remove from the stand and fasten to cage wires. Base disassembles from wheel making cleaning a breeze. Wheel measures 6 5/8" long, 4 1/4" wide and 7 1/2" high. Hand wash and dry thoroughly before use. Do not submerge wheel in water and do not place in dishwasher.