I usually keep a 5 pack of single .009 strings around in case one breaks. I get more mileage out of the whole set of strings that way. I prefer Ernie Ball, as I believe the alloy they use wears the frets less and they are a little more flexible, and I have had problems with D'Addario plain strings coming unwound at the ball end over the years, but this is what is in stock at Sam Ash for singles, and I am glad that Sam Ash at least keeps singles in stock, unlike some other major chains. So ,I usually just solder the ball end windings on these before installing to avoid that as a precaution. Good price, and in stock, good to have when you don't want to replace the whole set and your high E snaps, especially at a gig.