Amazon.com : Continental Bicycle Tubes Race 28 700x20-25 S80 Presta Valve 80mm Bike Tube Super Value Bundle (Pack of 5 Conti Tubes & 2 Conti Race tire Lever) : Sports & Outdoors
INNER TUBE Continental, 700c x 20 - 25 (Race 28) – Rivendell Bicycle Works
Chaoyang Bicycle Tire Road Bike Outer Tube Bicycle Inner Tube 700*23 25 28 32 35 38c Full Series - Bicycle Tires - AliExpress
Amazon.com: 16.9-28, 18.4-28, 480/70R28, 520/70R28 Tractor Tire Inner Tube with a TR218A Valve Stem for use in Radial or Bias Tires by TYK Industries : Automotive