Compatibility: This is specially designed for high temperature kit 300?, compatible with Ender 3 S1/3 S1 pro/ 3 S1 Plus, CR10 Smart pro 3D printer. Neck material: Made of the best titanium alloy TC4 and chrome copper in the market, with high precision machining. Titanium is a very strong material with almost 3 times lower thermal conductivity than stainless steel, resulting in a more defined fusion zone. Chrome copper effectively accelerates heat dissipation and provides better overall performance. Fine workmanship: The inner surface is smooth and burr-free; compared to ordinary heat break, the resistance of the print pull-in is greatly reduced, making the printing result much more accurate and sensitive. Good value spare parts: Includes 1 heater, 1 thermistor, 1 heating block, 1 silicone sleeve, 1 nozzle, 1 heat shield and 2 screws, all parts are machined with high precision. Note: Please make sure our products fit you before you buy.