Selectably locking medical coupling

A selectably locking male connector comprising:

• a first connection end;
• a central nozzle at an opposing end from the first connection end;
• a body positioned between the first connection end and the central nozzle, the body comprising an interior surface comprising opposing threaded sections alternating with opposing unthreaded sections, at least one opposing unthreaded section comprising a window, wherein the window is configured to receive a lug of a corresponding female partially threaded female connector;
• and
• a central bore extending from the first connection end through the central nozzle,
• wherein the selectably locking male connector prevents tubing misconnections between body systems.

A selectably locking connector system for fluid transfer comprising:

• a male connector, the male connector comprising
• a first connection end,
• a central nozzle at a second end opposite the first connection end,
• a body positioned between the first connection end and the central nozzle, the body comprising an interior surface comprising opposing threaded sections alternating with opposing unthreaded sections,
• a window in at least one of the opposing unthreaded sections, and
• a central bore extending from the first connection end through the central nozzle;
• and
• a corresponding female connector, the female connector comprising
• a first connection end,
• a cylindrical body at a second end opposite the first connection end,
• wherein the body comprises a female receiver, and
• a central bore extending from the first connection end through the female receiver,
• wherein the nozzle of the male connector is dimensionally compatible with the female receiver,
• wherein the selectably locking male connector prevents tubing misconnections between body systems, and
• wherein a female lug is centered in the window when the male and female connectors are coupled in a breakaway connection.