bag clamp. Just fold the bag closed and clamp it.
This version has a print in place spring that opens the jaws a little to help you slip it on the bag.
The author remixed this model.
I edited the design to add a print in place spring to open. nothing to see from the outside is different.
it is a plastic sping, depending on what material it is print out of will change how long the spring is good for. it is best to store the parts open. Even if the spring has taken a set to close it might open back up and work fine. The spring set does not prevent it from use. It just might not auto open.