Surefire Z68 TailCap, Fits Scout Light Weapon Lights, Protective Rear Cap Assembly, Tan Z68-TN The Z68 tailcap switch provides both momentary-on and constant-on activation press for momentary Scout Light or flashlight activation" press further to click the light into constant-on mode" click again for off. The raised guard around the push-button is a first line of defense against accidental light activation during operations or (for flashlights) while carrying the light in a pocket or holster. A lock-out feature positively prevents activation during tactical operations" transportation" or storage.