... kinds of butyl and natural tube in china. 3.50-4 Our certificate is ECE,DOT,CCC and so on ... motorcycleThe available size are as follows:250-4, 300/350-4, 350/410-4, 350-5, 350-6, 300-8, 300-10, 350- ... 8, 350-10, 400-5, 400-6, 400-8, 10*400-6, 10*500-6 ... /300-21, 350-16, 350-17, 350-18, 4.10-18, 90/90-18, 110/90-16, 130 ... 70-12, 120/70-12 etc. Butyl Tube 3.50-4