A cutting tool that can cut concentric ringed features onto a weld face of an electrical resistance welding electrode is disclosed. The streamer is to be towed in connection with a seismic survey, and the towing of the streamer produces a turbulent flow. The posting user defines a list of entitled users to be entitled to access the visual medium, said list of entitled users comprising at least one identifier identifying at least one entitled user, said identifier being associated to a parameter defining an access level to the selected visual medium. Thus, an inverter circuit may realized for a large-sized backlight without increasing a number of the balance transformers. The matrix coatings can be used to enhance biocompatibility and to control the local delivery of biologically active agents.