Ultraverse 20x4.0 Heavy-Duty Inner Tubes — 2-Pack

Heavy-duty 20x4.0 inner tubes built from thick butyl rubber — substantially more puncture-resistant than the thin stock tubes that come on most fat-tire e-bikes.

Size: 20 x 3.5/4.0 (89/102-406). Schrader valve (AV32, 32mm). Fits any 20x4.0 fat tire. Pairs with the Ultraverse 20x4.0 Fat Tire.

Sold as a matched pair. Keep the second one as a spare — flats happen, and having a tube on hand beats waiting on shipping.