A clip for engaging tissue includes a generally annular-shaped body defining a plane and disposed about a central axis extending normal to the plane. Each of the plurality of etched channels is divided into two or more separate channel sections separated by respective channel wall structures. The chemiluminescent device further comprises an actuator formed on the outer container of the chemiluminescent device in a location accessible to a user for breaking the frangible inner container and admixing the first and second chemiluminescent materials to produce a chemiluminescent effect. The extensive natural transmission range of low-energy quanta can also be used to receive potential information from systems. The blocking unit blocks the path between the switch and the engine control unit when it receives the block signal.