XS strings feature an ultra-thin and durable film coating that completely protects the wound strings while the plain steel strings receive our proprietary XT treatment, so all the strings in the set are protected from life-killing corrosion and contaminant build-up.
The coating is so thin that strings ring out the with the clarity and projection similar to an uncoated string.
D'Addario's NY Steel high-carbon cores in the wound strings and Fusion Twist-technology on all plain steel strings ensures unmatched tuning stability and increased break strength.
All of this with strings that have a smooth feel and don’t feel greasy or visibly fray like the leading film coated string.