A choice of two gauges of guitar strings. 8s are great for low resistance in bends, 11s are great for thick tone and maintaining tension in drop tunings.
8 set gauges: 0.008 - 0.038 (inch)
11 set gauges: 0.011, 0.014, 0.018, 0.028, 0.038, 0.048 (inch)