The RoHS compliant FFB series uses a non-impregnated polypropylene or polyester dielectric with a controlled, self-healing process that is specially treated to have a very high dielectric strength in operating conditions up to 105 degrees C.
The polyester dielectric version of this series carries rated DC voltages of 75-400V, with the polypropylene covering voltage ratings of 525 to 1,100V. The polyester dielectric allows for a Max Stray Inductance of 20nH and both versions allow for a 10% cap tolerance.