The Sunlite Utility Thorn-Resistant Tube (20x3.50-4.00) is engineered for fat bikes, beach cruisers, and heavy-duty utility bikes that demand superior puncture protection. Featuring a thick puncture-resistant layer on the tread side, this tube significantly reduces the risk of flats from thorns, debris, and sharp objects. The standard Schrader valve (SV) with a 35mm valve stem ensures easy inflation compatibility with most pumps. The free-wheel face width (FFW) of 104mm makes this tube versatile for a wide range of fat bike rim widths. Whether you're riding on trails, urban paths, or sandy beaches, this Sunlite tube offers the durability and reliability you need to keep rolling.