If you work on locos and decoders (e.g. run wires from loco to tender), you will eventually need thin, extremely flexible cables. These are not always easy to get. Responding to many requests from our customers, ESU offers you super thin cables (AWG 36) with an outside diameter of only 0.5 mm (0.02 inch), in all common DCC colors.
Yellow, super-thin cable comes in 10m bundles (30 feet).