Answer:
What sphinxes employ and players enjoy.
What is in seasons, seconds, centuries, and minutes, but not in decades, years, or days?
What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?
I can be found in seconds, minutes and centuries, but not in days, years or decades.
These are the bumpy parts of your digits
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?