1 name 2 material (fiberglass) 3 types (sliver, roving , yarn, short fiber) 4 length
After knowing specific custom code, you can check the elements for declaration at the custums net. The elements for declarationare mainly includes 1 material (glass fiber) 2 kinds (comb).
However, we can not determine the custom code of glass fiber which proprably includes in the 7019 part.