An RF power amplifier includes a plurality of amplifier cells. The method uses a virtual n-way conferencing module to provide the video conferencing, and an auto caller select module for causing selective video display. Upon detecting a secured communication, the network security module obtains a decryption key from the computing device to decrypt the secured communication. A pressing member for pressing the pressed surface of the insert to adjust a position of the peripheral cutting edge in the diameter direction of the tool body is disposed on the rear side of the attachment seat in the tool rotation direction.