DDT™ Drop Down Tuning bass strings lock in at even the lowest tunings thanks to DR’s Accurate Core Technology™ (ACT™). Coating the hexagonal core wire increases tuning stability and maintains intonation at any tension by helping lock the steel wrap in place. Now you can deliver notes at lower pitches that are clean, clear and in tune - No matter how hard you play! Accurate Core Technology™ was developed to reinforce the core wire and fill in imperfections along its entire length. Superior core wire is recognized as the foundation for rich tone, accuracy of intonation and durability.