Compatibility: for S1 Combo [Compatible 3D Printers]: This extruder hotend replacement is only compatible with for S1/ S1 Combo FDM 3d printers, not for other 3d printer models. Please confirm your 3d printer model before ordering. [Support High Speed Printing]: hotend with all-metal throat design makes the print head heated evenly and the filament flows smoothly in the throat nozzle to support high speed printing. And produced by a rigorous design and testing team, no leakage and clogging, you can easily start your 3D printing experience. Note: Installation guide not included, we strongly recommend you professional installation. Please check as much as possible to make sure the item is what you need. Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Color: As Shown Material: Metal Package Contents: 3 x Throat 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.