Advanced Illumination

 Total Internal Reflection Lenses
Many SureFire illumination tools use a total internal reflection (TIR) lens that is precision molded from a special cyclo-olefin polymer. The lens surrounds the LED, gathering virtually all of its light, which it reflects and refracts forward in an exceptionally tight beam that cannot be duplicated with a reflector.

 
Lithium Batteries
As a commitment to our customers and products, SureFire sells its own brand of quality 123-type lithium batteries at a very low price. Our WeaponLights and non-rechargeable flashlights use these lithium batteries because of their advantages over alkaline batteries. These advantages are:

Shelf Life — Lithium batteries can be stored 10 years and still supply up to 90% of their power. Alkaline batteries have a significantly shorter shelf life.

Temperature Tolerance — Lithium batteries function over a wide temperature range (-60° to 80°C, or -76°F to 176°F), although power is reduced at the extremes. In contrast, alkaline batteries function poorly below freezing and at higher temperatures. The temperature tolerance of lithium batteries also benefits their shelf life. Storing alkaline batteries at higher temperatures can kill them in a few months, but lithium batteries stored for years at similar temperatures can still function effectively.SF 123A Lithium Batteries

Power Density — For a given size (volume), lithium batteries produce much more power than alkaline batteries. For example, given same-sized batteries and the same power load, it would take about 2.5 alkaline batteries to match the power output of one lithium battery.

Weight — For a given size (volume) lithium batteries weigh about half as much as alkaline batteries. For example, an alkaline battery the size of a SureFire SF123 battery would weigh about twice as much.

Voltage — Terminal voltage for lithium batteries is 3 volts compared to 1.5 for alkaline batteries.

Voltage Maintenance — A lithium battery maintains fairly constant voltage for up to 95% of its life, depending on discharge rate. At moderate to high discharge rates, alkaline battery voltage drops rapidly due to internal battery resistance, which wastes power. The large reaction area provided by a lithium battery's wound-plate construction provides very low internal resistance, ideal for high current loads.

 
Shock Isolation and Protection
Certain SureFire illumination tools, such as our Special Operations Series flashlights, feature shock-isolated lamp assemblies. This shock isolation acts much like the suspension in an automobile, using springs and dampers to help prevent external forces from damaging lamp parts — particularly filaments. Additionally, a machined-in barrier prevents batteries from slamming forward into the lamp assembly. Note: SureFire illumination tools that use LED light sources don't need shock isolation because LEDs are inherently resistant to shock and vibration damage.

For exceptionally hard-recoiling weapons such as 12-gauge shotguns and larger caliber rifles, where batteries may be damaged by slamming together, SureFire recommends our special shock-resistant battery sticks. These consist of two, three, or four batteries assembled inside a heat-shrunk polymer sleeve, with each battery physically separated from the others by a load-bearing fiber washer, but electrically connected by a welded metal conductor. For low-recoiling weapons, such as 5.56mm self-loading rifles, standard SureFire SF123 batteries function perfectly.