This buckle / adaptor lets you use an ordinary 10mm rubber band if you can't get hold of a moulded strap. The gcode is for a single one on a 3i Mk3S.
The gcode is for an Original Prusa i3 Mk3S, smooth sheet, PETG, but I recommend making your own gcode with multiple instances in one print.
The author hasn't provided the model origin yet.