3M CI-21-840 Connector , 2–1 AWG stranded, 1–1/0 AWG solid, Connector O.D. 0.910 in (23,1 mm), 10 per case
This is a 2, 1 AWG stranded, 1, 1/0 AWG solid connector with a 3 inch body and a 0.90 in (22 mm) O.D., that are for splicing applications on aluminum or copper cable products
The 3M™ Connectors CI Series are for splicing applications on aluminum or copper cable conductors. The aluminum connectors CI Series are specially designed for use with 3M™ Pre-molded Power Cable Splice Bodies QS-I, QS-II and QS-III. These connectors meet the requirements of ANSI C119.4.