The 7720 strings have been around for quite a while. Although LaBella markets them as orchestral strings, they're actually quite useful for modern jazz, where a deep fundamental, bright tone, and "growl" is something players often gravitate towards.
Because they use the rope-core design (standed steel core, wound in a rope-like pattern) they have more flexibility and are a bit "lighter" feeling, even at the same tension/weight as a different string design. So, if you are looking for a lighter feeling string that has some of the character of, say, Thomastik Spirocores (kind of a benchmark string for big, detailed sound and growl) this might be an interesting alternative - and a considerably more affordable one, as well.
They have the kind of brightness that can balance out a dark-sounding bass, so for an orchestral player, that might bring some more detail to your bowed sound. They aren't quite as bow-friendly as some of the specific "arco" strings, but they are certainly fine under the bow.
The Light (7720L) set provides the same sound with a lighter tension. As with most strings, you'll likely lose a little acoustic volume with the reduction in tension - but if you're after the growl, this may be the set to get.
For the sake of accuracy, the package indicates that the winding on the Solo strings is "Nickel Chrome Steel," which may differ from the "Chrome Steel" of the Medium and light set. Not sure that it matters in any practical way...
LaBella does not list gauges on their packages, but I have taken the time to gauge all the strings using a digital caliper and present the following unofficial measurements of the 7720 sets for your reference:
- G .054
- D .065
- A .086
- E .112
- G .050
- D .060
- A .080
- E .104