20" x 4.0"/4.5" AV 32mm (102/114-406) Heavy Duty Self-Sealing Bicycle Inner Tube Key benefits - Reliable puncture protection: Pre-installed sealant quickly seals small holes and fine cracks, reducing the chance of roadside flats and the need for immediate repairs. - Long-lasting air retention: Thicker butyl/EPDM construction improves air tightness and keeps tire pressure stable for months, reducing inflation frequency. - Improved ride comfort and durability: Heavy-duty butyl rubber absorbs shocks and resists wear for a smoother, more durable ride. What this tube does for you - Stops small punctures automatically: The factory-filled sealant spreads into punctures and typically seals leaks within 5–8 seconds under normal conditions, getting you back on the road without a patch kit. - Performs in cold weather: Designed for normal temperature use down to -15°C, so it remains functional and helpful during colder rides. - Reduces maintenance and replacement: Thicker walls increase puncture resistance and wear life, lowering long-term maintenance and replacement costs. Features and specifications - Size: 20" x 4.0"–4.5" (fits 20x4.0, 20x4 1/4, 20x4.25, 20x4.5 tires) - Standard designation: 102/114-406 - Valve: AV (Schrader) 32 mm - Material: Heavy-duty butyl rubber with EPDM for improved elasticity and durability - Thickness: Increased by ~40% over standard butyl tubes - Air tightness: Up to 200% better retention compared with ordinary butyl inner tubes; maintains higher pressure for about 6–9 months after inflation (under typical conditions) - Self-sealing: Pre-installed sealant for automatic repair of small punctures Practical use scenarios - Fat-tire cruiser on mixed surfaces: Ideal for beach paths, packed gravel, and rough city streets where small debris can cause frequent flats. - Off-road and trail riding: Added puncture resistance and shock absorption help on rocky or root-strewn trails where friction and impacts are common. - Cold-weather commuting: Retains functionality and self-sealing properties in temperatures down to -15°C, useful for winter rides or early-morning commutes. Installation and care tips - Fit to compatible 20" x 4.0–4.5 tires and use a 32 mm AV (Schrader) valve rim. - Inspect tire and rim for sharp objects before installation to maximize sealant effectiveness. - If heavy punctures or cuts occur, replace the tube rather than rely on sealant alone. - Periodically check tire pressure and topping up as needed for optimal performance. Why choose this tube - Combines heavy-duty construction and pre-filled sealant for a practical balance of puncture protection, durability, and ride comfort. - Specifically matched to 20x4.0–4.5 tire sizes and standard 32 mm AV valves, making it a straightforward replacement for fat tires and wide single-track applications.