OMG, here are some at least ...interesting... phantasies. For me it is a (simpler) variant of the "Knebelkette" also called "Zwiesel", used mainly by police to move someone forward, eg. to the court or a lawer.
The tool is looped around the deliquent´s wrist and by slight turning the handle(s) it closes tight around the wrist. Against any -interesting- thoughts this tool was not intended for torture but for securing a (supposed) criminal and violent offender to prevent flight or an actual act of violence against the court or the lawer.
Here a refined variant is shown.
Regards,

1.JPG (96.52 KB, 60 downloads)
2.JPG (74.11 KB, 60 downloads)
wotan, gd.c-b#105

"Never look for sqare eggs" as a late owner of an original FHH-dagger used to say.