PLEASE ENSURE CAGE / CAGE DOORS ARE 14 INCHES TALL OR MORE! 's Silent Runner 12" Wide Wheel is the most innovative wheel on the market for its safety features and whisper-silent spin. Special night-illumination allows you to watch your pet run while they enjoy their natural dark habitat. Well suited to sugar gliders and other nocturnal pets! MEASURES: 13.5" tall on stand, 12" wheel diameter, 4" wide track, 4" diameter openings, 5" wide on stand. INCLUDED: Silent Runner Wheel, Stand, and Cage Attachment (Accessories sold separately) FEATURES: ✔ SAFE - The axle-free design eliminates a dangerous center bar, reducing the risk of fur/tail entanglement, pet wrap-a-round, curvature of the spine, and other injuries. ✔ SILENT - Innovative dual ball-bearings create a whisper-silent spin. ✔ NON-SLIP - Running tracks are textured, for excellent grip. ✔ SANITARY - Wheel completely disassembles for deep cleaning, no nooks for feces to hide in. ✔ SECURE - Closed off design with front plate for privacy, safety, and containment. With natural bean-shaped openings and a pet-preferred solid black rear wall. ✔ HIGH QUALITY - Wheel is made of high-quality plastic. ✔ JOINT PROTECTION - The stand allows for give, protecting your pet rom joint pain caused by running on a hard, fixed surface. ✔ IDEAL FOR - Hedgehogs, Rats, Sugar Gliders and other similar small animals (not suggested for chewers). What is dual ball-bearing technology? Two stainless steel ball-bearings within the back plate ensure the wheel glides smooth and silent. The bearings SPIN around the bolt instead of sliding and creating noise.