Heavy gauge 12 string guitar set designed for low tuning (on a "brand we cannot name" low tuned model --these strings are not endorsed by the namesake of that particular guitar). Phosphor bronze roundwound, .013 .013 .017 .017 .030w .013 .040w .017 .048w .028w .056w .036w, !!WARNING!! DO NOT USE THESE FOR A STANDARD TUNED 12 STRING -- it may damage your instrument. NOTE: In some cases, the nut may need to be reworked to accommodate the heavier gauge strings. Sealed in corrosion-free "NitroPack" packaging.