The NKK M Series of miniature toggle switches are of antirotation design, standard on noncylindrical levers, mates toggle and bushing.
The toggles have epxoy sealed terminals that prevent entry of solder flux and other contaminants. The NKK M Series also have an antijamming design protecting the contacts from damage due to excessive force on the actuator.

Epoxy sealed terminals
High torque bushing construction
Antirotation and antijamming design
Interlocked actuator block, lever and interior guide