Capacitor value?

[jimmyblacksmith]

What value is this polyester capacitor? Marked: MW-F .22/K

 

[Delta Prime]

K is tolerance plus or minus 10% of the printed value it's a .22 microfarad capacitor that has a DC working voltage of 630Volts.MW is the manufacturer's markings has nothing to do with the characteristics of the capacitor their in-house markings
How do you know it's polyester?