1. What is the difference between candlepower and lumens?
Lumens is what is used to specify the total amount of light coming from any light producing device, and candlepower refers to the highest value of the light intensity to be found anywhere in the lights "beam".

Lumens tell you how "powerful" the light-producing device is, be it a light bulb of any type, a flashlight, or a car headlight. Candlepower tells you how tightly focused the beam is, assuming the light source has a lens or reflector to focus the light into a beam.

Lumens can be measured quite accurately, using an instrument called an integrating sphere, and identical lights would all have similar lumen values. It is an important quantity to know when comparing different lighting products, as it tells you how much light each one produces.

Candlepower can also be measured accurately, using a light intensity meter to measure luminous intensity, and then by applying the appropriate formula, which takes into account how far, the meter is from the light source. The problem is that the value measured depends on where in the beam you take the measurement (the highest value found is what is normally used), and on how well the beam is focused. It is not unusual for candlepower values to vary greatly from unit to unit on otherwise identical lights due to small differences in focusing or reflector tolerances.

Candlepower specifications (if accurate) are really only useful in comparing lights if the lumen values are also provided. If two lights had similar lumen values and one had a higher candlepower value, what it would mean is that light had a more tightly focused beam. This may or may not be an advantage depending on what the light is to be used for. Using candlepower values alone to compare the "power" of different lights, particularly those from different manufacturers, is likely to be at best misleading, particularly since there is a history of overstating actual candlepower values in the flashlight industry. For this reason Sure-Fire does not use candlepower to specify the performance of its lights, but instead uses accurately measured lumen values exclusively. Customers interested in selecting SureFire lights having higher light intensity values can do so by choosing models having larger reflectors, such as our turbo heads.

2. Can I remove the bulb from the reflector?
On many lamp/reflector assemblies the answer is no, because the units are precision focused as a unit, at the factory. On other models, the lamp in mounted in a precision focused carrier that is removable from the reflector (Millennium series systems, Executive series lights…)

3. Why did the lens on my flashlight melt?
It is possible that a Lexan lens will melt if accidentally activated while covered for an extended period. In the event that this happens, replacement lens kits are available.

4. Is my SureFire flashlight waterproof?
Most SureFire lights are water resistant but not waterproof. As of 2001, all models excluding the E1, E2, and G2 have diaphragm-sealed, lock out tail caps that make them far more water resistant than earlier models.

5. The tail-cap button on my SureFire flashlight won’t move, is it broken?
The tail-cap button assemblies have very little travel so there is often a misconception that it is broken. If the flashlight features a lock out tail cap and the button will not move, apply additional pressure on the button until it breaks free and can rattle loosely inside the cap.

6. Can I adjust the focus of the beam pattern?
To achieve a flawless bean pattern, all SureFire lamp and reflector assemblies are pre-focused, therefore cannot be adjusted.

7. The lamp in my SureFire flashlight failed, what should I do?
In extremely rare cases, a SureFire lamp may fail. With all of our flashlight models, the bulb is permanently attached to either the reflector body, or a bulb holder. In either case the entire lamp assembly must be replaced. If this problem occurs, a replacement lamp is available from Surefire directly at 714-545-9444.

8. Why doesn’t the tail-cap on my SureFire flashlight click on and off?
Clicker type mechanisms have historically proven unreliable and usually have a short life span. It is our philosophy that a intermittent tail-cap, combined with a bezel constant on system, is far superior.

9. Can I use SureFire brand lithium batteries for other applications?
SureFire lithium batteries can be used in various electronic applications such as cameras or any other device requiring 3-volt lithium batteries.

10. Are SureFire Nitrolon (polymer) flashlights as durable as the aluminum series flashlights?
In some cases the Nitrolon flashlights are more durable than aluminum flashlights, due to the fact that Nitrolon is extremely impact and dent resistant.

11. Why are some of the parts of my hard-anodized SureFire flashlight different shades?
The gray to green appearance of the aluminum parts on a SureFire flashlight is produced by a hard-anodizing process. Unlike most anodizing processes these parts are not dyed, but rather colored by the coating itself. Different colors result from factors such as surface finish, blend of aluminum, etc. The performance of the coatings is so superior that the variance on color is well within factory specifications.

Our complete selection of Surefire Flashlights can be seen HERE.