4 Feet each of E-24 Yellow, Green and Blue single "tinned" wire (41 strands) 24 gauge superflex wire made by Wire-Plex® in the USA. 24 gauge is the correct wire to carry the correct voltage to e units and what Lionel uses. Wire-Plex® provides this very same wire for the circuit boards that are made for Lionel. No Black writing on the wire like other wire out there. Used on Lionel e unit contact fingers 100-45 and 100-46. This wire is great for low current use on e Unit re-wiring & accessories. I personally measure and cut off 4 feet off master roll as shown in picture 1. These are not on rolls. We also offer different sizes and different types of wire.