EPCOS TDK B43762 series Capacitor Suffix

EPCOS TDK B43762 series Capacitor

What is the difference between suffix M600 and M000?

Example part number B43762A5478M000
Datasheet for this item does not identify what the M0 suffix is calling out while listing options only with M6 suffix.

Information provided by the supplier:
M000 => External insulation PVC sleeve.

M600 => External insulation PET sleeve.

There are no electrical differences to the parts, only the type of sleeve it has.