Recently purchased this as I used to use it exclusively a decade ago. It had been pretty difficult to find F-One Oil in the EU market for a long time. Fortunately, Thomann has had these in stock for some time, excellent!
I believe it's the best 100% natural essential oil blend for your unfinished fingerboards. I was also using Sandberg Fingerboard Oil which is also a 100% natural oil. However, I find Music Nomad superior as they are a specialised company in this niche field.
I used to experiment with cold press essential oils made from lemon, citrus, mint and grape seeds for an alternative fretboard care oil. I had even written an article about this.
Almost all the other products (except Sandberg Fingerboard Oil) in the market are petroleum-based oils with added synthetic lemon (Limonene) molecules. (Check out my article on Google by searching for my nickname).
Basically, most of the time we buy mineral oil with added essence and fragrance. But F-One is different. It smells like nature!
If you are picky about what you put on your guitar fretboard, this is it! 100% recommended by a guitar nerd!