Swimline 36-in x 36-in 1-Seat Black Inner Tube 2-Pack in the Pool Toys & Floats department at Lowes.com
Amazon.com: Water Sports Original ItzaTube Inflatable Black Inner Tube Large 36" Diameter : Everything Else
Water Sports Original ItzaTube Inflatable Black Inner Tube Large 36" Diameter | eBay
Amazon.com: River Tubes for Floating Heavy Duty, Pool Float Adult, 53" Inflatable Float Tube for Beach Lake Rafting, River Floats with Mesh Bottom : Toys & Games
GoSports Duratube 44" Heavy-Duty Tire Tube - Black – GoSportsOutdoors.com