PRS Signature Series strings feature a proprietary alloy, giving PRS Signature strings a greater magnetic property for a louder, brighter sound. Soldered ends extend string life and help the guitar stay in tune. Nickel-plated steel strings with hexagonal-shaped high-carbon steel core for long-lasting, vibrant sound. All PRS Signature Series strings come in corrosion-free packaging to keep the strings fresh. Made in the USA. Our strings are wound in pairs accordingly: 1st and 4th, 2nd and 5th, 3rd and 6th Made in the USA. Individual string gauges: .009, .011, .016, .024, .032, .042.