Box Clasp (Tab Insert)
Box clasps are two-piece clasps that open when you push down on the exterior lever of a wedge-shaped piece of metal, compressing it so that it slides out of the opening. Push it back in and it clicks into place.
Box clasps are easy to use, but often do not have as much strength as lobster claw clasps. Box clasps can be plain or decorative and you'll find them in a variety of shapes and sizes.