Optical disk

An optical disk comprising:

• a disk body having a first surface adapted to be printed thereon, a second surface opposite to said first surface and adapted to store optical data, and a central through hole extending from said first surface through said second surface and confined by an annular hole surface, said disk body further having a cap seat flange that extends radially and inwardly from said hole surface and that is formed with a plurality of mounting holes therethrough;
• a cap body including a cap plate disposed in said through hole, said cap plate having a top side adapted to be printed thereon, a bottom side, and a peripheral portion on top of said cap seat flange, said cap body further including a plurality of hooking arms that extend from said peripheral portion at said bottom side and that extend slidably through said mounting holes;
• and
• biasing means connected to said cap seat flange and said hooking arms, for biasing said cap body to move said cap plate toward said cap seat flange.