Prevue Pet Products 6 Inch 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 Inch long, 4 1/4 Inch wide and 7 1/2 Inch high.