What is this device? It's about 8cm long when closed, and has little indentations on the top piece and raised lines on the bottom. Possibly it could be used to crush garlic etc.?
It's a lemon/lime wedge juice squeezer.
Only place I've ever really seen them used is in British Indian restaurants.
Pop a wedge in the gap, squeeze the handles, juice can be poured with reasonable accuracy from any of the fluted edges. No messy fingers.
Image from Amazon