I have an unopened/unused set of Thomastik-Infeld JF344 Flatwound Bass Guitar Strings 34"L that I bought in advance of a back-orderm on an Epiphone Jack Casady Fretless Bass that just arrived. I bought them, because the specs said that bass would ship with D'addario strings, but it actually shipped with Gibson flatwound strings, which I didn't know exist these days, and I like the sound as it is so I never opened this box of TI flatwounds.
Note that these are lower tension than most flatwounds on the market. My recollection is that they have a round core (like all pre-1970's strings) vs. a hex core. I used this type of string for many years on a Godin fretless bass (before I sold it) and quite liked the TI feel, but I use LaBella's on my Precision Bass so I don't have another bass to use these on today.
These have skyrocketed in price due to the just-imposed European tariffs, and will likely go up again. They now sell for $102 or more; they were still "only" $78 during holiday discounts when I bought these a few months ago. I always give bigger discounts for people buying more than one item for sale.