RF4: This might refer to a series or model designation used by a particular manufacturer to identify a range of soldering iron tips. The "RF4" designation could denote a specific shape, size, or material composition of the soldering tip.
T2-OIS: The "T2-OIS" part could represent further specifications or characteristics of the soldering iron tip. This could refer to attributes like the size, shape, coating, or specific features of the tip, although without precise context or manufacturer details, it's challenging to determine the exact meaning of this part of the designation.
Equipment
Compatibility