13"x4" (13x4.00 8) Black Low Profile Pneumatic Mobility Tire with C9328 Tread Inner Tube:With Angled Valve Tube you might want to consider Control & Junction Boxes you might want to consider topping your brain bucket with this absolutely awe inspiring Sawblade Crest for bike & scooter helmets Mounting hole spacing is approximately 1 3 4" x 3 1 4" (four threaded holes) Because many of our mobility customers prefer using pneumatic tires as they offer a smoother ride than solid or foam filled tires or with an inner tube that has a 90 degree angled valve stem which makes the job of inflating the tube much less frustrating