1. Isolated Silicone Sleeve: The silicone sleeve can prevent the fan from cooling the heat block, helping to stabilize the temperature—useful and practical. 2. EASY TO : This is an upgraded version improved over the original. The original A1 hotend extrusion head does not feature replaceable nozzles. The Xirbbo A1 extrusion head comes with threaded hardened steel nozzles that can be removed and replaced, reducing operating costs. This A1 hotend extrusion head allows for the exchange of special replaceable nozzles. 3. Temperature Printing: The hardened steel nozzle is made of hardened steel material with higher thermal conductivity, greater strength, stronger oxidation resistance, and a longer lifespan. It supports temperature filaments ≤ 320°C, and the removable nozzle is easy to , saving time. 4. COMPATIBLE MODEL: This nozzle hotend kit features an improved threaded nozzle structure that is detachable and individually replaceable. Suitable for A1 or A1 mini 3D printers.