Overview: The extruder is almost the most important part for 3D printer, also the most difficult part to calibrate. we have made necessary design to prevent «jammed» problem. I can’t emphasize anymore how important this is, other sellers don’t have this and would cause many problems. Features: (1)The extrude is with thermistor sensor. (2)Compatible with ABS and PLA 1.75mm. Tips: While using with PLA filament, please always remember to keep the fan on, otherwise it might get jammed and ruin the hotend. PLA is more easier to get jammed, so it might require some patience to practice. For ABS, we would also suggest to keep the fan on, as this is also better. also remember to purchase filament from good reputation seller, as the filament is very important! ( default for this is with 0.4mm nozzle, and suitable for 1.75mm filament ) Specifications: (1)Nozzle:0.4mm (2)Voltage:12V/24V (3)Motor Model:SL42STH40-1204A (4)Nozzle Flow Rate:24cc / h (5)Thermistor Tpye:NTC 100K 3950 (6)Sports Shaft Speed:10-100mm Motor Parameters: (1)Model:SL42STH40-1204A (2)Step Angle:1.8∘ (3)Rated Voltage:2.55 V (4)Rated Current:1.7 A (5)Phase Resistance:1.5Ω (6)Phase Resistance:2.3 mH (7)Number of Lead Wire:10-100mm