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One of the coolest details about the Spider-Man design used in Civil War and Spider-Man: Homecoming is its mechanical, expressive eyes—a staple of Spidey in comics and animation, but rarely attempted in live action. It works great on screen, but fans are proving adept at recreating the effect for their costumes, too.

Aptly named Spidey cosplayer Lenses Factory HK has spent the past couple of months developing a mechanical version of the new Spider-Man face mask—which triggers the eye shape on the costume’s mask going from full to squinting with a mechanism operated by the user’s jaw. All it takes is opening and closing your mouth.

It’s a simple trick but one that’s really effective. They’ve even refined the design even more to make the transition smoother, and more accurate to the shape of the lenses on the new movie suit.

Peter Parker—and I guess Tony Stark, considering he made this version of the suit—would be proud of such ingenuity. The good news is, if you don’t want to attempt to make it yourself, Lenses is going to start selling a very limited run of masks like this come April. Just in time for Spider-Man: Homecoming!