The Fenix LD01 is extremely small, not much bigger than the AAA cell it uses. It has three modes: Medium -> Low -> High. These modes allow the user to select the best compromise between brightness and runtime for any given task. The Fenix LD01 uses just one common AAA battery, and, thanks to its negligible size and weight, it is perfect for Every Day Carry (EDC). Moreover, its solid reliability has been strictly tested and proven.