This a soft clear line is easily configured to the space you have. It's able to bend at a sharp angle without kinking.
See Hex Fittings or Size H Ferrules for this clear line.
This line line equals the following equivalent 1:1 size at each scale.
1/25 scale = 1 1/2"
1/16 scale = 1"
1/12 scale = 3/4"
1/8 scale = 1/2"
Depending on your scale, typical uses are smaller coolant hoses and larger fuel lines, as well as other transfer lines.
Each package contains one coil of .059 x 12"' clear ;line.