Gauges: 13-17-26w-36-46-56 (Medium) ROUND CORE.
80/20 Bronze wound strings are often called old-school, vintage and/or bright bronze and were the most popular (only) alloy used to make acoustic strings until the introduction of phosphor in the early Seventies. 80/20 bronze wire is made from 80 percent copper and 20 percent zinc. 80/20 bronze provides balanced highs and lows with a slight increase in mid-range that seems the make the notes cut-through a little more.

By design, round core strings must be handled carefully so that the outer winding does not come lose. On guitars that have a an eye in the tuning post, it is important to install the string and tune to pitch before cutting the excess string off. On guitars where the tuning post has a hole down the center which requires the string to be cut prior to placing the string down the post hole, it is important that to you first make a 90 degree bend before cutting the string. It is best to make that 90 degree bend about two inches longer than the post where you will be installing the string. Once you have made the bend leave about one-half inch before cutting the string then place the bent section inside the tuning post and tune to pitch. Be aware that it takes longer for a round core string to "settle" in and it requires many more tugs, but once installed and settled in, they are amazing.