Surefire KL4

The KL4 converts your SureFire E2, E2E, E2O, or E2D flashlight to high-intensity LED technology. This is no typical low-output LED system -- the KL4 uses selected 5-watt LEDs to produce a maximum of 65 lumens of light, bright enough to qualify for tactical use. LEDs not only provide the ultimate in shock-resistance, they also provide extended runtime since they produce light more efficiently at low wattage; a battery too depleted to run an incandescent lamp can still produce usable light from an LED. The KL4 consists of a hard-anodized head assembly fitted with a 5-watt LumaMax™ LED, an anti-reflective coated Pyrex® window, and digital current regulation circuitry. This circuitry matches the LED's current requirements with the battery's output, maintaining a more consistent level of light output for the useable life of the batteries, unlike unregulated lights that are subject to a steady decline in light intensity beginning shortly after activation. This circuitry also protects the LED module from current and heat-related damage. Many LED flashlight manufacturers inflate the light output and usable runtimes of their LEDs, but SureFire provides realistic output and runtime specifications based on scientifically obtained measurements. Athough any LEDs can produce negligible light output for over 100 hours, the amount of useful light produced is of a shorter duration.