Low G single
4th string for Low G tuning. They label this as a tenor low G but it's the same .028" that their concert low G as well and really it can be used for soprano as well. So we are just going to call it a single low G.
The main difference in this string and other wound low G's is that it has an Aquila nylgut core. This makes it lower tension than most other wound low G's which can help create a more equal balance with the other plain strings.