Preferably nickel rounds. Currently, my Lakland USA P-style bass is wearing Dunlop Flats. I am thinking of putting Dunlop Nickel Super Brights on that Fender Jazz, which is currently wearing Daddario XLs after they set it up at the dealer before shipping it to me. I am not a huge fan tension of XLs so I am guessing DSB will be perfect (lower tension to XLs).