Plug and Play: Remove the old extruder and install the hot end to start. (3D accessories are pre-installed) Nozzle and hot block: The seamless connection between the nozzle and heat break accelerates heat dissipation at the nozzle and improves thermal insulation at the heat break, helping to prevent clogging. Please note that there may be a slight color difference or variation in appearance, which does not affect performance. This hotend kit is compatible only with Neptune 4 3D printers. Color: As shown Material: Aluminum + Brass Package Contents: 2 x Printing Pickup Nozzle Kit (includes 2 x 0.4mm nozzles) Only the items listed above are included; other products are not included. Note: Lighting reflections and different display settings may cause slight variations in color between the image and the actual item. Measurement error allowance: +/- 1-3 cm.