The Surefire E1B Backup is a Ultra compact (finger length), dual-output LED flashlight with extended runtime and tactical-level output. The Surefire E1B was developed as an everyday-carry flashlight for undercover officers and as a backup light for patrol officers - but it's also ideal for outdoor, self-defense, and everyday use by civilians. The Surefire E1B Backup Flashlight features a virtually indestructible, electronically regulated light emitting diode (LED) that, on its "high" setting, produces a smooth, tactical-level beam (enough light to temporarily overwhelm the night-adapted vision of an aggressor) with four times the output, of a two-D-cell flashlight. And it continues generating tactical-light levels for 1.3 hours on a single battery. On its "low" setting, the Surefire E1B generates five lumens of light that's perfect for reading a map, checking an ID, or navigating a dark pathway, and generates useful light levels for 37 hours. And this Surefire Flashlight's click-on/off tailcap is programmed to instantly deliver maximum output when its pushbutton is depressed, a critical feature in law enforcement and tactical applications where a lot of light is frequently needed immediately. Rounding out this flashlight's features are its unique "melted" styling - no knurling or sharp edges to catch on clothing - and two-way pocket clip, which lets a user carry the Sure Fire Backup bezel up or down, whichever he or she prefers.