The FNIRSI HS-02A Soldering Iron Internal Heat Nut Kit is a professional portable soldering solution designed specifically for 3D printer heat-set insert installation and precision electronics work. Powered by a 100W intelligent heating system, it provides rapid heat-up, precise temperature control, and stable performance for embedding brass threaded inserts into plastic components. The kit includes 7 heat-set insert tips (M2–M8), making it compatible with a wide range of brass insert nuts used in 3D printing. Featuring a 0.96-inch IPS color display, USB Type-C PD/QC fast charging, adjustable temperature from 100°C to 450°C, and ergonomic aluminum alloy construction, the HS-02A is ideal for makers, engineers, hobbyists, and repair professionals.