I would like to know how I can edit the printer category to add some monitors ?

I create 4 monitors in "Canon Printer" template. I want to create the same monitors in "HP-Printer" template but I can't do this because the name of the monitor is already use. And if I add a new monitor in "HP-Printer", I don't see my custom monitor that I created for "Canon Printer". 

Help me please :)

Regards,

Delatte K.