S.I.T. Foundations Stainless Steel or S.I.T. RBs (Rock Brights) stainless steel. These 2 are as close to Rotosounds Swing Bass as you can get. I use to use the Rock Brights because they use the same stainless steel #430. The Foundations came out about a year ago. More flexibility to them. Just Strings carries them or just Google SIT Bass strings & you can buy them direct. I have no affiliation to this company. I'm just love their strings & was a formal Rotosound user.