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 Steel Nozzle diameter: 0.4mm Movement axis speed: 40m Nozzle flow rate: about 24cc/h Cable Length: 100cm Print Material: ABS PLA 1.75mm Cooling fan operating voltage 12V Extrusion head heating voltage: 12V, preventing 5-9 ohms, 500MM cable. K-type thermocouple 500MM link line. NTC 100K B=3950 1000MM stepper motor line Cooling fan: 12VDC 0.12A 40 x 40 Aluminum heatsink Extrusion head voltage 12V, power 40W Normal working temperature: 190 to 250 Black 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