... supply many kinds of butyl and natural tube in china. 3.50-4 Our certificate is ECE,DOT,CCC and so on ... , truck, motorcycleThe available size are as follows:250-4, 300/350-4, 350/410-4, 350-5, 350-6, 300-8, 300-10 ... -19, 275/300-21, 350-16, 350-17, 350-18, 4.10-18, 90/90-18, 110/90-16, 130/90 ... /70-12, 120/70-12 etc. Butyl Tube 3.50-4