Lulzbot TAZ Dual Extruder 3D Printer Tool Head Compatible with TAZ 4 and TAZ 5 3D printers. Prints 3mm filaments. Not 1.75mm compatible Comes pre-assembled with quick connect headers for TAZ 4 & 5 wiring harness for simple installation. Also includes spool holder and feed tube for second reel of filament Includes two Budaschnozzle 2.0c Hot ends with .35mm Nozzles Not recommended for flexible filaments like NinjaFlex and SemiFlex. See the LulzBot Flexystruder or FlexyDually for printing flexible materials Firmware update required when installing this tool head