Unusual Square D breakers

Anyone familiar with these breakers?

they are “keyed” breakers, they use a hex key (allen wrench) to operate. amperage and indicator arrow stamped in screw head. those are 20 amp, one is on and two are off in the picture.
they are used in places where you have breakers you don’t getting flipped, like computer circuits, security lighting, etc., commercial and industrial mostly

Square D QOK, the K is for key type.

http://forums.mikeholt.com/showthread.php?t=182867&p=1816199#post1816199

Thanks!

Why are they used?

Thanks for posting. I’ve never seen that one.

they are used in places where you have breakers you don’t getting flipped, like computer circuits, security lighting, etc., commercial and industrial mostly

Also used in industrial security circuits and fire suppression systems. To make sure only authorized personal operate them