SainSmart Assembled J-head Hotend Nozzle 0.4mm for 3mm Nozzle Fitting, 3D Printer Printing Filament Reprap MakerBot Kossel Delta This J-Head Hot End is designed based on other nozzle. It's very simple by reducing the number of custom machined parts to a bare minimum. The J-Head Hot End can easily and well interface with the most popular RepRap extruders. The filament path is same with the one of an already proven design, it can be used to print reliably with both ABS and PLA. Removed the heat sink and added a series of vents to provide cooling. To reduce weight, an aluminum nozzle is used.