Longsword Whisperhead SERSR

The Longsword Whisperhead SERSR (Suppressed Extreme Range Sniper Rifle) is a weapon in Deus Ex: Human Revolution, appearing available from the start of the game with the Tactical Enhancement Pack.

Background
The Longsword Whisperhead SERSR is a weapon developed by Steiner Bisley.

Characteristics
This is a highly accurate long-range, bolt-action weapon that features a built-in sound suppression system that renders it virtually silent, making the shooter in cover almost undetectable at long range. The sniper can send large caliber rounds against distant targets, thus making it a one-hit kill weapon against non-armored enemies. It will not, however, kill 'heavy' enemies (let alone Ogres) with a single headshot.

It should be noted that silence does not make for invisibility. Should one merely wound a target, rather than either miss or one-shot-kill, the target is likely to go hostile and immediately target you even if you might have been expected to have been well out of his field of view (crouched on the rooftop of a nearby tall building, for instance). A miss, on the other hand, will usually not alert the target of your location and if it is noticed at all will tend to direct them towards the impacted surface.

Locations

 * Sarif Manufacturing Plant, one is added to the player's inventory at the start (If you have the Tactical Enhancement Pack).
 * Detroit, can be found in Seurat's storage room near the basketball court.
 * Hengsha Pangu, one is located on the maintenance catwalk.
 * Montreal Picus, one is located in the sub-basement.
 * Found on a red container on Belltower Dock, left to the main gate.
 * Found at Omega Ranch in storage room with a Level 4 security keypad.

Behind the scenes

 * The Longsword Whisperhead SERSR has been probably inspired by two rifles, the AIG Asymmetric Warrior for the adjustable stock and the Remington MSR - Modular Sniper Rifle for the bolt and the receiver.
 * In third person view, the laser from the laser sight mod comes out of the front of this tube, despite that in the inventory it is shown as a module mounted underneath the weapon.