【Size】This bike tire tube fits 700c tires with 35mm to 43mm diameter. So, this tube can fit 700x38c and 700x40c bike tube
【High Quality】 Our bike inner tubes are made of high quality butyl rubber material. Better air tightness, heat resistance, and durable. Suitable for most of bicycles wheels
【NOTE】Make sure inner tube match with the size of tire; Inflate a little air before installment, to avoid crack or damage during installment; Install the valve correctly, which must be 90° with steel, and the nut must be well locked; After installment, please check the tube is at the right position between steel and tire, make sure the tubes are not clamped by them; Then inflate the air according to pressure standard of tire
