The Thomastik 4 Bass Strings JR 344 43-89 is a set of strings for a 4-string bass guitar featuring a round wound construction. This unique sounding string has a construction similar to it’s flatwound counterpart but with more edge. The round outer-wrap is a small diameter nickel alloy winding that adds slightly more bite to the upright style tone without the typical roundwound side effects of excessive string squeak and premature fret wear. The set is designed with a lower tension and gauging to increase ease of playability and reduce strain on the instrument’s neck without sacrificing output.
These strings are not for everyone, they are very unique in their sound and feel.
They sound quite warm but very growly with good mid range presence. They're definitely not very sparkly on the high end.
Now the feel. They are like no other strings. Very supple feeling, the E string is extremely thin. You have to play quite softly in order to accommodate for the loose tension and feel. If you can manage, these stirngs feel like cheating, they're so easy to play. These are definitely more biased to fingerstyle playing.
I use jazz flats and jazz rounds on all my basses. They cost more than most strings but they can't be beaten for playability. The rounds are a lot brighter - maybe a bit too low tension if slap is your thing but a good all round string. The flats have a great jazz sound and are much easier to play than most other flats.