Magma Acoustic Guitar Strings TRANSPOSITOR RE-D NEW SOUND - Phosphor Bronze Wound (GAT-D)Medium Low pitched range Transposition in a tone lower than normal guitar tuning Solution for singers with a low pitched voice who need to transpose down Possibility of using the 6 strings of the guitar in certain tones for strumming and accompaniments String material: Phosphor Bronze Designed for acoustic guitar, it does not exert extra tension on the instrument Tension: 143. 52 lbs