SIZE: [2-pack] The replacement inner tubes are for 16×6.50-8, 16×7.50-8″ inner tires .please check the size before you buy it.Material AND HIGH QUALITY: The tire inner tube is made of butyl rubber which is better in absorbing shocks and aging resistance.USAGE : The inner tire tubes are usable with garden carts, tractor carts, hand trucks, trolley, flat carts , wheelbarrows, mowers, and more.EASY INSTALLATION : The heavy duty inner tubes are easy to install. It is take probably 20min to install the tire tubes. No special tools.PLEASE NOTE: Please inform in time when you need help, and we will try our best to deal with it for you.Product Description Material: Butyl Rubber. Package including: 2 x Inner Tubes. Come with TR13 straight valve stem. The tire tubes are usable with garden carts, tractor carts, hand trucks, flat carts , wheelbarrows, mowers, golf cart and more. Heavy duty and durable. High quality ,easy installation ,your best choice.