it is made of natural rubber; 20% and 35% rubber content; it has E/V, D/V ,A/V; 1X20FT can load 56000-60000pcs; bicycle tube:we can produce 28x1.1/2,26x2.125,24x2.125,20x2.125,16x2.125,12x2.125 tube with E/V,D/V,A/V;it is made of high quality natural rubber, which is 20% and 35%;it is export to USA, middle east, africa and India; 28x1.1/2 bicycle tube