Cover where the power is turned on fell off

Cover where the power is turned on fell off
Hi, the cover on my right earbud fell off. The rubber gasket around the circumference along with the plastic circle piece that has what looks like the hand held portion of an old phone and the thin gray rubber piece underneath the hard plastic circle. Is that part replaceable? I am concerned the internal parts that are now exposed will get damaged. In addition, now I cannot turn it on and off

ANSWERS: