A ratchet wrench includes a parts replacement structure that ensures effort-saved and smooth operation and prevents parts from getting lost. Then, the ink is absorbed into a primary recovery portion mounted on a movable body. Such waveform generators can be used in or with a laser driver. The width of the second conductor is less than the width of the first conductor and the second conductor is substantially centered on the second side of the insulator relative to the width of the first conductor to reduce fringing of an electromagnetic field resulting from a transmitted communication signal. Wind turbulences are determined and compared with a predefined wind turbulence threshold value.