This hollow black vinyl line is extremely soft and bends easily.
Inside diameter is .031"
This soft line equals the following equivalent 1:1 size at each scale.
1/25 scale = 1 5/8"
1/16 scale = 1"
1/12 scale = 3/4"
1/8 scale = 1/2"
Depending on your scale, typical uses are coolant, fuel and oil lines. Also, at larger scales, A/C lines to/from the compressor and fuel supply and return lines to/from the fuel cell or gas tank.
Use Pro Tech Hex Fittings sized at .060. These will have to be drilled out slightly.
Each package contains 12" of .068" hollow black tubing, by Parts by Parks.