A plastic piece that sits on top of the zipper handle that is slightly wider and above the actual zipper.
If you zip up something you can snag anything - your favorite pants or dress, or even body parts (Ouch!), ruining expensive items or harming your self.
The plastic guard is wider than the zipper handle and also wider than the two sides of the zipper. If something is blocking the way the plastic piece simply stops the zipper rather than snagging anything on its way.
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