Socket Switch "Keep On" Cover

I have a socket with a plug in it that runs my entire aquarium setup & cannot be switched off. I already have a label but this does not prevent the switch from actually being turned off. So I designed and printed this. It can either be permanently attached using a few small drops of super glue or less permanently attached using Blu-Tack or thin strips of double-sided tape. It features a very small slot which will not fit even the smalles fingers but will allow it to be switched off if it ever needed to be on purpose using something thin such as the corner of a ruler, slotted screwdriver, toothpick, ect….