The gauges are stated on the back of the pack as .010 .013 .022 .036 The description says, "Flat-wound" - (smooth comfortable feel). The pack states "Polished" - (even more comfortable). A and E Chrome steel. Nickel and chrome are more magnetic than iron, so more output to magnetic pickups. (Not applicable to me). This set only has 2 wound pairs. The Perfection set has 3, but I'm not sure if that would make the lighter wound string more prone to breaking? I may try those in future for comparison.