If you do electronics repair, soldering, or heat shrink tubing work with an 850-style hot air rework station, this nozzle kit is super handy. It gives you 12 different steel nozzles to direct and focus the hot air exactly where you need it. You get a range of round nozzles (from 3mm up to 12mm diameter), square nozzles (10x10mm and 12x12mm), and even double-layer square nozzles for more specific tasks. The different sizes and shapes let you work on everything from tiny SMD components to larger chips. They're made of steel for durability and high-temperature resistance. This is a replacement/upgrade kit – the actual heat gun is NOT included. It's perfect for replacing a lost or damaged nozzle, or just expanding your tool's capabilities for more precise work. A must-have accessory kit for anyone serious about electronics repair.