The Hakko B3478 Tube Unit 1.2mm with Switch for Hakko FM-2030/2027 Soldering Irons and Hakko 373 Solder Feed System. The tube unit contains the heating element and thermocouple that regulate the temperature of the soldering iron, and the switch allows for easy on/off control. This product is designed for use with the specific models of soldering stations mentioned and can help keep your station functioning properly.

• It features a durable and long-lasting design, ensuring a consistent and reliable performance
• The tube unit is equipped with a switch, allowing for easy control and switching between different soldering tips
• It is compatible with a wide range of soldering tips, making it versatile and suitable for various soldering applications