3M CIR-21 Splice Butt Compression Aluminum Connectors are a compact inline butt splice in the 3M CIR Series, designed to join aluminum or copper conductors with a crimped compression connection. The connector body is tin-plated aluminum for reliable conductivity and corrosion resistance, and it meets ANSI C119.4, delivering a code-compatible repair option when used with 3M CIR repair kits. The CIR-21 variant is specified for inline butt splicing with a crimp range around 1/0–1 AWG, and is intended for use with molded rubber splice kits such as the 5411R and 5412R in 15 kV applications.
