This is most likely a ceramic capacitor.
The numbers on the disk denote the capacitance in picofarads.
If the number starts with a . then the value is below 1pF, for example .01 is 0.01pF.
If there are two digits to the number, then that is the capacitance in picofarads, for example 22 is 22pF.
If there are three digits then the first two digits are the capacitance, and the third digit is the multiple of ten, so 473 is 47000pF, or 47nF (4, 7 and 3 zeros).
A letter in the code indicates the tolerance or precision of the capacitance value: