Here's what D'Addario say about the XS 12-53 Phosphor Bronze Coated Strings:

Born from our greatest breakthrough in string innovation, XS Phosphor Bronze strings have the longest life of any D’Addario acoustic guitar string. The XS coating gives our warm, balanced phosphor bronze strings maximum life, with an uncommonly smooth feel. Made with a NY Steel core, phosphor bronze wrap wire and Fusion Twist technology, XS coated acoustic guitar strings have incomparable break strength and tuning stability, in addition to their dramatically increased lifespan. 12-53 Light strings are our most popular acoustic gauge, providing a nice balance of playability and tone.

PRODUCT FEATURES:

- XS Phosphor Bronze strings have the longest life of any D’Addario acoustic string, thanks to the ultra-thin XS film coating.

- Phosphor Bronze wrap wire provides tried-and-true D’Addario acoustic tone, with beautiful balance and warmth suitable for all musical genres.

- With a NY Steel core and Fusion Twist technology, XS Phosphor Bronze offers greater break strength and unmatched tuning stability—staying in tune 131% better than standard acoustic strings.

- XS Phosphor Bronze strings come with a code which you can register to earn Players Circle points.

- XS coated acoustic strings are made in the USA—drawn to our exacting specifications at our New York production facility

SPECIFICATION:

Gauge : 12-53 Light
Coating: XS
Number Of Strings: 6
Set Type: Sets
Wrap Material: Phosphor Bronze