La Bella 750N-B Black Nylon L

First of all, warning, these strings don't have the tension you might expect. Full setup required when putting these on a bass.
Then the sound is very cool but it's special, there are little genre where that sound fits in my opinion.
Something to try for fun, but quite expensive, so if you're hesitating but not sure of the sound, don't take them.
I played mine for like a couple months, and went back to flats or rounds.
Also in a band live situation, they don't cut through.

I bought a set of these to use on the bass i use primarily for reggae gigs. But after about 3 gigs i took them off as they sounded just like roundwound strings when they need changing. The bottom end was no better than my roundwound strings with eq. I have put them on my acoustic bass guitar and that is a much better place for them.