A video source device includes a cipher unit. , begins to melt at about 35 to 80 C. The conductive seal visually indicates the write prohibit state. The invention also provides method enabling said composition to be cross-linked and power cables including insulation andor a sheath containing the composition obtained by the method. 0 nm is 75% or more, and an ozone decomposition catalyst powder is disclosed. This folding protection mechanism makes the foldingunfolding of the ping pong table easier and more user-friendly, so even one person is able to handle the table set up without difficulty.