Ernie Ball Extra Slinky Acoustic Guitar Strings (2150) are engineered using 92% copper, 7.7% tin, 0.3% phosphorus wire wrapped around a tin plated hex shaped steel core. These Ernie Ball Extra Slinky acoustic guitar strings have a light gold colour with clear, warm and resonant sound.

Slinky Extra String gauges are 10-14-20-28-40-50.