Hello, this is the LD41 2015 version from Fenix . It is a 4AA searchlight with a max lumens of nearly 1000 lumens thanks to it’s cree XM-L2-U2 led. The LD41 stands for limit defying and is the third generation flashlight ever since it’s father , the LD40, and it’s older brother the LD41 2014 version. A great companion for hiking , caving, ecc.. basically any type of outdoor activities. There are color filters and diffusers that are made specifically for this flashlight and are available online. Thanks to it’s primary battery source of AA’s this flashlight can run off lithium, alkaline or NI-MH offering a more vast and reliable source of economical and everyday-use type of batteries.