Specification: Material: Brass Screw Thread: M6 Nozzle Diameter: 0.4mm Input Diameter: 3mm Total Dimension: 12.5x7mm / 0.5x0.28 inch (L*D) Package Content: 4 x Brass Nozzle NOTE: Small accessories please keep away. After replacing the nozzle please recalibrate the distance between nozzle and build plate to ensure the quality of print parts. How to Replace Nozzles? 1: Turn on 3D printer heat the nozzle and heat block to the target temperature (PLA: 180-220 ABS: 240-280). 2: After heat finishing close printer take spanner to hold the heat block. Then use socket screwdriver to screw old nozzle extruder out. Notice: Please don t touch the old nozzle and heat block to avoid burning. 3: Spanner keep to hold the hear block use the socket screwdriver screw the new nozzle in make sure tight.