D'Addario XS Coated Acoustic Guitar Strings, Phosphor Bronze, Custom Light .011-.052, XSAPB1152-3P, 3-pack [Domestic Genuine Product] The 'XS Series' acoustic guitar strings bring a new breeze to the coated strings category. Employs an ultra-thin ePTFE film, less than one-tenth the thickness of a human hair. Gauge: Custom Light .011-.052