STI Rear Ultra Duty Inner Tubes 4 mm thick 18"x 110/120/100

18"x 110/120/100 STI Motorcycle Tubes are strong stronger strongest the all new UD ULTRA HEAVY DUTY TUBES ARE STRONG VERY STRONG AND UTILIZE A NEARLY BOMBPROOF 4MM THICKNESS the Ultra's are made from high qulity butyl rubber with a 4mm thickness.