PRS Signature Series Strings feature a proprietary alloy, giving PRS Signature strings greater magnetic property for louder and brighter tone. The soldered ends extend string life and help the guitar stay in tune. Nickel-plated steel strings with hex-shaped, high-carbon steel core for long-lasting, vibrant tone. All PRS Signature Series Strings come in corrosion-free packaging to keep strings fresh. Made in the USA.PRS Signature strings provide a louder and brighter toneNickel-plated steel strings with hex-shapedHigh-carbon steel core for long-lasting, vibrant toneCorrosion-free packaging to keep strings fresh String Gauges: Heavy: 12, 15, 24, 32, 42, 52Made in the USAPRS Item No. 100148:006:001:004Shop like the pros at Sam Ash Music, where discerning musicians go for premium guitar accessories.