Brudda Iz used a regular high G Martin string set, but this is how he used the strings.
- For the G string, he used his C string and tuned it low.
- For the C string, he used his E string.
- For the E string, he used his G string.
- He left the A string in the normal place.
(source: Brudda Bu, FleaMarketMusic.com Forum) Brudda Iz used a tenor uke in low "G" tuning.