This looks like a stainless steel line, but it's a small gauge stainless steel wire wrapped in a gray nylon jacket.
This is ideal for a throttle cable, parachute release cable or elesewhere where a steel cable is housed in a jacket.
The wire core is springy and doesn't droop like a soft line and it isn't rigid like an aluminum line.
This line equals the following equivalent 1:1 size at each scale.
1/25 scale = 5/16"
1/16 scale = 3/16"
1/12 scale = N/A
1/8 scale = N/A
Each package contains one coil of .014 x 18"