2-Pack 20" Fat Tire Tubes 20 x 4.0/4.5 AV33mm Schrader Valve Heavy Duty 20" Fat Tubes Compatible with 20x4.0 20 x 4.25 20 x 4.3 20 x 4.4 20 x 4.5 Fat Tire Bike Tubes https://www.amazon.com/dp/B0953C6986/ref=cm_sw_r_apan_i_TEH4FWDA8AXFH7S6TBB2?_encoding=UTF8&psc=1