4099 Flatwound : Very nice old school flatwound.

I got these for a Jazz Bass and I absolutely love them. They are sort of midway between Pyramid Golds and Rotosound 77s.

-Not quite as thumpy as the Pyramids, more sustain (and not the characteristic "dead" E-string of the Pyramids).

-Slightly fatter, warmer sound than Rotosound 77s (and not the clanky, metallic sounding E-string that never seems to mellow out).

And yet they kinda remind me a bit of both. Certainly much closer to Pyramids/Rotos than say LaBellas or GHS flats.

To give an idea how they sound: On my Jazz Bass I would say they are pretty close to but SLIGHTLY fatter/thumpier than early Zeppelin/JPJ.

Tonal balance is more even across the strings than with either the Pyramids or the Rotosounds. These Optima flats are better allrounders then either of those in my opinion (but of course this also means they are lacking some of the quirky charm of the Pyramids/Rotos).

Tension feels high but not extreme. These are not very flexible strings though. If you like your strings light and flexible you probably won't like these.

Highly recommended if you like old school flats with a very "European" vibe. Especially if you wish your Pyramids Gold were slightly less thumpy or that your Roto 77s were just a tad warmer/fatter.