2227 Nickel wound Ultra Slinky is the electric guitar string set is constructed with nickel-plated steel wire wrapped around a hex steel core for the classic Slinky sound that guitarists have relied on for decades. Ernie Ball Ultra Slinky combines the winning features of the popular Regular Slinky and Power Slinky strings in one set. The extreme playability of Regular Slinky blends with the crisp, low-end of Power Slinky for a rich, versatile sound.