From CNC Kitchen:

• Adapter + Tips for quick change of required size
• Sizes: M2,x, M3, M4, M5, M6+1/4″, M8
• ORIGINAL CNC Kitchen Soldering Tips for easy installation of short and standard threaded inserts
• Compatible with soldering irons that use T18 and M900 standard like Hakko, Lonovo, Sremtch, etc. Dimensions see product pictures
• Max. recommended operating temperature: 280C
• Soldering Stations:
• Quality Option :Hakko(recommendation):
  Hakko Soldering Station

  Cheapest Option:
  Here