La Bella 7GPUL Phosphor Bronze UL, Set of Strings for Acoustic Guitar, String gauges: .009, .012, .015, .025w, .036w, .048w, Tension: Ultra-light, Material: Phosphor bronze, Made with an exclusive bronze and tin alloy for a brighter tone and longer life than average phosphor bronze strings, Round wound, The improved sealed packaging prevents tarnishing and guarantees the freshness of the strings, Made in USA