MS3112E12-8S is a miniature cylindrical box mounting receptacle connector designed for aerospace and military applications. It features a shell size 12 with 8 solder contacts arranged in a 12-8 insert pattern, meeting MIL-C-26482 Series 1 bayonet coupling specifications. The connector employs an environmental resisting service class ("E" designation) with solder contact termination, providing robust electrical connections in demanding environments. It supports multiple insert rotation positions (W, X, Y, Z) for flexible installation configurations. The connector is commonly used in avionics, military equipment, and industrial systems where reliable, compact interconnections are required in harsh operating conditions.