I use the battery in a Fenix TK21 XM-L U2 and a NiteCore Chameleon CU6 Especially when Fenix is the good voltage level of the battery over the entire period is noticeable. While it breaks both with "Cheap Batteries" and also with brand cells with higher Kapzität quite quickly, deliver the 2600 over the entire period enough electricity, and the lamp will turn very late return one step.
