Adopting the latest American Cree XM-L LED, the Fenix TK21 is the first high intensity, compact outdoor flashlight to use XM LED with the side mode switch button. Fenix TK series flashlights feature a powerful, tough and waterproof to IPX-8 standard design, which is great for many extreme outdoor environments. Powered by two CR123A batteries or one 18650 rechargeable battery (Li-ion), this light features multiple brightness levels and is a perfect combination of extremely high intensity and ultra-long runtime. The TK21 is your reliable partner for all of your outdoor adventures.