Yeah, they have a mechanical arm that holds a pen and duplicate the motions of a signature. And then has a feeding mechanism so that you can sign a whole gaggle of documents automatically.

They used to be a contraption that with linkages that held a bunch of pens. More of a "multi-pen". It's funny that signing papers got to be labor intensive enough of a problem that they had to invent productivity devices in the 1800s. I could imagine that if Trump had to manually sign every Jan 6 pardon, he probably would have just let them rot in prison instead.