12mm Square Plastic Push Button Switch

This is a nice quality pushbutton.
It is well machined with nice clean threads and no scratches on the face and fits well, and the terminal screws are high quality.
The 'button press feel' is pretty good since the overall travel is very low and everything is substantial and metal with a decent amount of resistance on the spring. There is not a clear break / tactile feeling at the exact point of switch activation / deactivation. This did not matter for your application, which was switching low voltage power to a dangerous handheld box with a lithium battery, high voltage transformer, and some external terminals.