The Fenix PD25 is perfect in size, measuring only 3.70" in length, crafted of aluminum with a maximum output of 400 Lumens using a single CR123 battery or 550 Lumens using a single rechargeable 16340 battery. The PD25 has four different brightness modes, making it perfect for any low-light area. The 16340 battery can be recharged with any compatible lithium-ion charger, so you can get hundreds of uses out of the same battery. Features an intelligent memory circuit- Remembers the last mode used before being turned off, digitally-regulated output maintains constant brightness, low-voltage warning function to remind you to replace the battery, reverse polarity protection to protect from improper battery installation, anti-roll, slip-resistant body design, tactical tail cap switch with momentary-on function and side switch on the head for output. Includes rechargeable Li-ion battery, lanyard, holster, body clip and spare O-ring.