The heating block is with special heat insulation cotton.Using 42mm high quality stepper motor.Heating rods, 100K NTC Thermistors , motor leads up to 100cm.304 stainless steel heating rod.Specification:Material: Stainless SteelNozzle diameter: 0.4mmMovement axis speed: 40mNozzle flow rate: about 24cc/hCable Length: 100cmPrint Material: ABS PLA 1.75mmCooling fan operating voltage 12VExtrusion head heating voltage: 12V, preventing 5-9 ohms, 500MM cable.K-type thermocouple 500MM link line. NTC 100K B=39501000MM stepper motor lineCooling fan: 12VDC 0.12A 40 x 40 Aluminum heatsinkExtrusion head voltage 12V, power 40WNormal working temperature: 190 to 250Black and green as a group, red and blue as a group, then connected to board, if you want to change direction,please exchange a group between two group.Package Includes:1 Piece 12V 0.4mm MK8 Extruder with Cable :It is 12V, Operating temprature 190-250, please don't over 280, otherwise parts easy to damage