At Biker's Choice, it's not only their passion but their personal promise to provide customers only the best products the world has to offer. They know their products like they know each other, because they ride what they sell. Biker's Choice Heavy-Duty Inner Tubes are top quality inner tubes for all the popular sizes of heavy cruiser tires. Tube Specifications: Tire size: 3.25/3.50-19. Valve type: TR-6 (straight metal stem (8 mm diameter)). Note: Ensure the inner tube size matches tire size.