Ernie Ball 2153 12-string Slinky Acoustic Phosphor Bronze String Set (09 - 46)
Made from 92% copper, 7.7% tin, 0.3% phosphorus wire wrapped around tin plated hex shaped steel core wire. These strings  provide a mellow, ringing sound, with excellent clarity. Gauges .009*.009, .012*.012, .020w*.009, .026*.012, .036*.020p, .046*.026,