A plated copper-alloy heater block. Its dimensions match Volcano V2.
This copper alloy transfers heat much more efficiently than aluminum or brass heater blocks, allowing for faster printing.
When doing high-volume printing with an aluminum heater block, it is usually necessary to increase the hot-end temperature significantly higher than the intended filament melt temperature in order to compensate for slow heat transfer. This leads to inconsistent results, though, because filament is not always coming out at the same speed. During lower-speed segments of the print, the heat transfer "catches up," and the filament will heat up beyond what is intended. This copper-alloy heater block solves this issue by allowing you to print at your usual temperature for whatever filament you are using, because there is less of a need to compensate for slow heat-transfer with higher temperatures.