I really like the: "MARTIN GUITARS M600 NEW UKULELE STRING SET"; & Thomann are selling them at a very competitive price at the moment. Although they are soprano/concert sized ukulele's I find that they fit a tenor sized ukulele (which is my preferred size of ukulele), instead of using the "Martin M620 Tenor Ukulele Strings". I find that fluorocarbon strings produce a louder sound, & these particularly give a bright, lively tone. When they are completely broken-in & have settled down I also find fluorocarbon strings & these Martin Strings in particular hold their tuning much better than other types of strings. All in all, I find that the "MARTIN GUITARS M600 NEW UKULELE STRING SET" are a great value strings & will improve the sound quality & performance of most ukulele's. "Pleasant Strumming".