Abstract: A multi-tool device is disclosed including a separable hinge architecture and an open-ended wrench mechanism. The open-ended wrench mechanism including a frame member with integrated or separate outer jaw, and a sliding and rotating inner jaw, and a spring to bias the jaws closed. Various means to arrest the motion on the stroke are presented. The hinge embodies two parallel rotational joints through positive or negative orifice allowing mechanical fastening of two multi-tool modules to be paired and locked rotationally through common means in selectable positions.