This connector is a green, 400 kcmil with a length of 3.750 in (95,3 mm), a 0.760 in (19,3 mm) I.D. and a 1.187 in (30,1 mm) O.D.
The 3M™ Scotchlok™ Aluminum Connector 20012 is for use with copper or aluminum conductors. These aluminum connectors feature color coded end caps for identification. Contact aid provided in connector barrel is compatible with poly/EPR insulations.
Scotchlok Aluminum Compression Connectors - Data Sheet (PDF 37.2 K)