This is a small black twisted multi-fiber line.

It is very flexible and can be bent at sharp angles
The OD dimension is .008" or .20mm. 

This soft line equals the following equivalent 1:1 size at each scale.
1/25 scale = 3/16"
1/16 scale = 
1/12 scale =
1/8 scale   = 

Could be used for small black "braided" lines to the blower manifold, injector plate or injectors.  

Because of its twisted fiber construction, it could be used for a cable or rope.

Each package contains one coil of .008" x 18" soft line