A golf club head and a removable weight that is received in a receptacle of the golf club head. Also, because the tablet of the present invention contains fine granules having the average particle diameter such that it will not impart roughness in mouth, it can be administered easily without discomfort at the administration. When the two pastes are mixed, they start to react to each other while injecting out. If a session is to be transferred, resource reservations associated with establishing a second IMS session for the transfer can be bypassed by informing the IMS system, either explicitly or implicitly, of the relationship between the terminals involved in the transfer. The mark size of input NRZI data is discriminated and the power of overwrite pulses is varied in accordance with the discriminated mark size, optimizing read power, peak power and bias power for overwrite pulses, to supply optimized pulses to the laser diode.