The Fenix E18R is truly an impressive flashlight. You get a maximum 750 lumens from a 2.36-inch flashlight, weighing only 1.17 ounces (without the battery) AND it is rechargeable via an included magnetic charging cable. You can always trust the construction of a Fenix flashlight. The oxidation-resistant aluminum body and the ultra-thin optical lens are built to withstand every-day use as well as the harshest elements. The E18R operates with two battery sources: the recommended rechargeable 16340 battery or a CR123A battery as a backup source or a source when in below-freezing temperatures.