DDT? Drop Down Tuning Bass Strings go right into tune and lock in thanks to Coated Core Technology? (CCT?), a coated hexagonal core wire that locks the stainless-steel wrap wire in place to increase stability and maintain intonation at any tension. Now you can deliver notes at lower pitch that are clean, clear and in tune. Change tunings and DDT's lock right in and require little to no adjustment between play. Coated Core Technology delivers extended life and increased stability The stainless steel wrap on a hexagonal core wire delivers extra brightness needed for heavy gauges Especially designed for players who use drop-down tuning