A cylinder head for an internal combustion engine has hydroformed port liners positioned within selected ports, either exhaust andor intake ports. Tools are also provided which allow rapid and unequivocal identification of the event in biological samples. The openings where the lower, first protection film is removed are larger than the openings where the upper, second protection film is removed, so that the upper, second protection film has an overhanging structure. The coupler system improves the bandwidth in a coaxial cable transmission system . Therefore, the links and the pin can be connected to each other securely and firmly with a sufficient holding force to the pin in the axial direction.