What front derailleur is this? Want to replace/upgrade Hi I've bought a foldable bike and am thinking of changing the derailleurs to Shimano, but I could not figure out what type it is.

The link the to the bike is:
https://www.forever-bicycle.com/html/show-22-29-1.html

It says MICROSHIFT FD-42F could not find it on Microshift's website .. and googling seemed to only give results to the product pages of the bike itself. Any chance that this might be a customized item?

To further this question:

If this FD is a customized item .. what are the other alternatives I have? Or is advisable to just switch to internal rear hub?
Its called a "braze-on" front derailleur.

The matching opposite format is a "band-on" or "band clamp" and goes around the seat tube.



Be careful when torquing the single bolt in your braze-on fitting.  Too loose and it will move while shifting.  Too tight and it will strip the thread and move while shifting.  



Separately - the cable is disappearing downward, so it can be described as "Bottom Pull" or "Bottom Normal"

I can only see one other chainring, so this seems to be on a bike with a double chainring.

Answer Its a braze-on bottom-pull front double mech.

If your question is about groupset - look closely for engraved or embossed model numbers.  I can't recognise it.

The front derailleur is not a critical part and given its more about brute force than finesse you can get away with a very low groupset front mech perfectly well.   Sora and Tiagra will work fine with a 105 or ultegra rest-of-system, with some minor variance based on chainring separation distance.