Are you a dummy sometimes, like me?

Of course not. But we all make mistakes! Some of us have rigid flags, some of us have sketch opto sensor end flags.

For those with sketchy, cheap, tin foil-esk flags, protect yo' neck with the opto guide.

Nothin fancy, but in the event that your cat, child, etc decide to poke around at your printer, rest just slightly more assured that your flag will make it between the rails!