久久影院午夜理论片无码_少妇人妻在线视频_成人av无码一区二区三区_波兰女人毛茸茸

NR

NR natural rubber

產品詳情

Generally speaking, natural rubber refers to an elastic solid made from natural rubber latex collected from the Brazilian rubber tree through processing steps such as coagulation and drying. Natural rubber is a natural polymer compound with cis-1,4-polyisoprene as the main component. Its rubber hydrocarbon (cis-1,4-polyisoprene) content is above 90%. It also contains A small amount of protein, fatty acids, sugar and ash.

����av����һ��������������,�������޾��þþþþ���������

久久影院午夜理论片无码_少妇人妻在线视频_成人av无码一区二区三区_波兰女人毛茸茸