These tubes are often replacement for 20x 4 Bicycle tubes as they are thicker to withstand flats.
Moose 16" Heavy Duty Inner Tube w/TR-6 Center Metal Valve Stem (3.00-3.50) Fits Tire Size: 3.00-3.50 Heavy-duty tubes made specially for off-road and motocross German made, these are the sturdiest, highest quality tubes on the market 3mm thick natural rubber construction helps resist pinch flats
⚠ WARNING: California Proposition 65 www.P65Warnings.ca.gov.