CMD2673997 Butt Wire Splice Connector, Red, Insulated. From RS PRO, a selection of insulated ferrules or Butt Connectors designed for crimping electrical wires. The tube-shaped terminals act as a solderless cable joint allowing electrical current to flow safely from one wire to another. Professionally designed using high-quality materials, RS PRO’s range of butt splice terminals are used to repair, change or lengthen electrical circuits.