Zipper pull loop is a remixed design with one side completely flat for the easy printing without support.
Please use the original Zipper pull base from marqss then assemble two pieces to a zipper pull.
Multiple stl files with various curved loop width also available. Try using one of them if the zipper hook is very tight.
The author remixed this model.
One side of zipper pull loop is completely flat for the easy and clean print. The loop width at the curve is now ~2mm instead of the original ~1mm.