The Hot-End peek isolation part is used to keep the heat in the lower part of the Hot-end and to keep the upper part of the Hot-end cool.
For FELIX 1.0 up to FELIX 3.1
Filament diameter: 1.75 mm
NOTE: If you buy this part, because it is melted down. It is strongly recommended to replace the thermistor as well. People have reported melt down of this part. The root cause is 99% a bad thermistor.