Please Note: The complete hot end kit is only for PrusaMK4, not for PrusaMK4XL, as their thermistors are different. It is a good replacement for PrusaMK4 hot end parts. These separate structures are more conducive to changing nozzles and saving costs. The bimetallic neck is made of titanium, with good heat dissipation, fast heating 500, smooth 0.4um, good heat insulation. The thermistor is suitable for PrusaMK4 Thermistor-104NT-4-R025H42G (300max). Only for PrusaMK4, not for PrusaXL Heating Rod/Heater-24V40W The heating block is suitable for PrusaMK4 It is made of aluminum alloy and can meet most printing needs. Only for PrusaMK4 Note: Installation guide is not included, we strongly recommend professional installation. Please check as carefully as possible to ensure the item is what you need. Tips: This product can be continuously updated, due to different batches, the actual product may have slight differences or color differences, which does not affect the use of Color: as shown in the picture Material: Aluminum Alloy Package Contents: 1x Aluminum Heating Block 1x Thermistor 1x Heater 1x Silicone Sleeve 1x Hardened Steel Nozzle 0.4mm 1x Bimetallic Neck Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to be slightly different from the actual item. The allowable measurement error is +/- 1-3cm.