DDT™ Drop Down Tuning Electric Guitar Strings maintain their intonation at lower tunings thanks to Coated Core Technology™ (CCT™), a coated hexagonal core wire that locks the nickel-plated steel wrap wire in place to increase stability and maintains intonation at any tension.  DDTs go right into tune and deliver clean and clear notes.  Change tunings and be surprised how DDT's lock right in without constant adjustment.