THE PERFECT REPLACEMENTS: AR-PRO offers the perfect replacement inner tube for 3.50-8'' (8'' rim size, also fit 4.00-8, 3.50-8, and 3.25-8 tire) of hand trucks, lawn mowers, yard trailers, wheelbarrows PREMIUM QUALITY: Our inner tubes are made of premium, heavy duty rubber, yet for less cost from the OEM GUARANTEED PROPER FIT: Our inner tubes are approved by the mechanic to ensure the quality meets or exceeds the OEM ones EASY INSTALLATION: It takes less than 5 minutes to replace all tires