This is a latching hemostat. It works, but I wouldn't use it for medical purposes. :-)
Offset the handles a bit to unlatch.
It's based on a design by the former ICI Ltd. whose patent has expired.
Makes a handy clamp for small things. Yet another chip clip? You could modify it so the jaws close to a fixed opening if you're holding things together for gluing...
Because of the nature of the plastic (I used ABS) the hinge has a limited life. I kept flexing one until it broke, about 70 flexes. When it breaks, print another.
Print & trim. I added the wings because in earlier attempts the tips and the latch mechanism would curl up off the built platform. I didn't want to do the amount of trimming a raft would require.
The size is about as large as my Thing-O-Matic can print, about 10 cm (4 inches) long. It can probably be scaled down some, but keep an eye on the hinge mechanism. If it gets too thin it probably won't work too well.