This hard line equals the following equivalent 1:1 size at each scale.

1/25 scale = 3/8"
1/16 scale = 1/4"
1/12 scale = 3/16"
1/8 scale  =  1/8"

Depending on your scale, typical uses are injector lines from distribution blocks into a supercharger hat or manifold, oil lines, nitrous lines and brake lines.  Can also be used for pneumatic and fire suppression lines. 

Use this for brake lines in 1/16 scale.

This is easy to bend and shape to your installation and is already highly polished looking.  

Use Hex Fittings sized at .020. These will be a bit large, but a drop of epoxy will make it work.

Each package contains one coil of .016 x 18"'