For a technical user who expects all-around performance and features out of their headlamp but still values a small size and compact package. This user has the need to run the lamp on alkaline batteries if caught away from a power source for a long expedition. Dual-Fuel: Maximum flexibility to utilize either the rechargeable Lithium Ion BD 1500 battery or Alkaline cells (included) 400 Lumen max output PowerTapTechnology allows instant adjustment between max output and dimmed power Integrated battery meter display shows % of power remaining Settings include proximity and distance modes, dimming, strobe, red LED night-vision and lock mode Brightness Memory allows you to turn the light on and off at a chosen brightness without reverting back to default setting Red night vision has dimming and strobe modes and activates without cycling through the white mode Multifaceted optical efficiency lens technology IPX8: Waterproof-Tested to operate at least 1.1 meters underwater for 30 minutes. I