Ernie Ball Coated Slinky Titanium RPS Acoustic Guitar Stringsstar rating 5KinamApril 1, 20101, 2 ball end was wounded with Titanium like materials. I used 11-52 sized strings and first impression was very good. Bright sound of 80/20 was proper and tune level was exact. I thought the tension was lower than Elixir and D'Addario strings. Good quality even though non-handmade string!