These heat breaks are used in our SE300, XST, HE280, and ERIS Hotends.
Precision machined in-house from stainless steel. We designed it our way years ago. Our design allows the PTFE tube all the way down to the top of the heater block while most hotends stop at the top side of the thin section. By allowing the PTFE down to the block, your much less likely to jam because the filament is staged at the transition point right before the filament becomes fully melted.
A great design for temps up to 280C and provides a jam free experience.
Our design for our hotends.
To experiment with temps over 300C, non-PLA, non ABS, try our "jet" insert. The jet increases the melt zone and move the PTFE tube up away from the high temperatures.