They're .045"-.105" and have been on there a couple of weeks. No problems, great sound, and they're tight enough. It had TI JF324's (should be JF344, but I had the med scale strings and tried them) on it before and the strings were too loose for certain stuff with my right hand. The tension with the LaBellas is fine. A slight change in amp EQ was necessary, no big surprise. The LaBellas are there to stay.