"D addario XL series strings use the highest grade nickel used in gutar string manufacturing. Their sound and playability are often considered unmatched. They are a highly magnetic string that produces maximum volume and brightness with electric pickups. The nickel plated steel formula wrap used on XL strings maximizes the the electronic characteristics of the instrument. Popular for Rock, Jazz, and most styles of music. These are the "EXL" version. The "E" in "EXL" stands for environmental version. We support the environment, and so should everyone. They are the same strings in an environmentally friendly package. They have done away with the plastic wrapping, and minimized packaging waste. "
