MS3112E12-3PY is a miniature cylindrical box mounting receptacle connector designed for reliable electrical connections in aerospace and military applications. It features a shell size 12 with solder contacts and bayonet coupling mechanism compliant with MIL-C-26482 Series 1 specifications. The connector is rated for environmental resistance with an open wire seal configuration, providing protection against moisture and contaminants. Key dimensional specifications include a shell size of 12 with a contact diameter of 0.812 inches and a maximum length of 1.438 inches. This connector is commonly used in avionics, military equipment, and industrial systems where robust, compact interconnections are required in harsh operating environments.