The stainless steel alloy of the 2613 Helix HD Bass Guitar Strings has an inherent bright and cutting timbre to it. It gives a Bass String an unforgettable “stainless” tone.The Helix strings go a step further to optimize tone and sustain in the patent pending way they are designed and constructed. Just like the NPS Helix Bass, Helix SS Bass features the Hyper Elliptical Windings (compressed from side to side), which gives Helix more Mass and Tone, as well as extended life. This Hyper Elliptical winding is what gives Helix its special feel—a more relaxed feel, with a lot less squeak and sliding noises than normal strings. Gauges: .045, .060, .080 and .100