Frequently Asked Questions

Please review the following frequently asked questions, the User's Guide for each product and the product comparison chart.  If you have a question after reviewing this material, please contact us by e-mail or phone.

LEDs and light measurement standards

What is an LED?  

What are lumens, spec sheet lumens and out-the-front lumens?  

What is the ANSI/NEMA FL-1 standard?  

How far can I see with my light?  

What are lumen-minutes?  

Are all white LEDs the same color?  

What is a color rendering index (CRI)?  

Why are warm-white and neutral-white LEDs less efficient than cool-white LEDs?  

How long will the LED last?  

Advanced technologies

What is constant power LED regulation?  

Why are your lights calibrated?  

What is burst mode?  

What is visually even brightness spacing?  

What is tint control?  

What are Acme threads?  

What is an anti-reflective (AR) coating on the lens?  

What is military Type 3 hard anodize?  

What is aluminum titanium nitride (AlTiN)?  

What is a baked-on ceramic finish?  

Operational considerations

What is the logarithmic nature of my eyes?  

What is the practical difference between different light outputs?  

How can I see further?  

How can you achieve the lowest cost of ownership?  

Which beam pattern is best?  

Do you overdrive your LEDs?  

Why do flashlight runtimes vary?  


How long will my battery last?  

What's the differences between primary and rechargeable lithium batteries?  

Why are rechargeable batteries treated special?  

What are the differences between 123, R123, 16340 and R17345 batteries?  

What are the differences between R17670, 18650 and R19670 batteries?  

Other questions

Can I use my flashlight as a dive light?  

How do I install the pocket clip?  

What is the purpose of the external switch cap O-ring?  

Why does the flush button not tail stand?  

Where are your flashlights manufactured?  

What are CE, RoHS and WEEE?  

Copyright © 2014 by HDS Systems, Inc. All rights reserved.
Trademarks and trade names are the property of their respective owners.
Updated January 2014