Our Vinyl Insulated Butt Connectors have been PVC injection molded with funnel entry for fast, easy wire insertion. Terminals have “V” groove serrations to provide maximum contact and tensile strength after crimping.These terminals are constructed from pure copper (Alloy 110), annealed & electro tin plated. Electro Tin plating provides exceptional corrosion resistance. Insulator sleeve is color-coded for wire size and identification.