The disclosure provides a communication apparatus that can accurately measure the available bandwidth of a communication path between itself and another communication apparatus by performing measurement communication in accordance with an execution frequency. The wrench body includes a handle, a driving head mounted on an end of the handle, and a locking portion rotatably mounted on the driving head and inserted into the mounting hole of the driving member. The composition provides specific inhibition of cyclooxygenase-2 with little or no effect on cyclooxygenase-1. The optical sheets are placed in turn behind the diffusion plate.