HawkEye Xbow XH-II

The Xbow XHII is a weapon in Deus Ex: Human Revolution.

Background
The Xbow XHII is a light and foldable crossbow manufactured by Stasiuk Arms Inc. It has a 4 pulleys system and specially shaped bow segment. This weapon uses Guillaume Tell Golden Arrows, which are polycarbonate, carbide-tipped, fin-stabilized bolts and are manufactured by Kaiga Ltd, a Russian weapon manufacturing company.

Characteristics
This powerful and compact crossbow allows its user to pin targets to walls. It's the perfect stealth weapon, removing threats with minimal disturbance. The crossbow can be equipped with an electronic sight that calculates the lead distance required to hit a moving target.

Bolts fired from this weapon can be retrieved after a kill around 30% of the time, otherwise they will break. (It should be noted that retrieving the bolts must be picked up as a normal object, not looted from a corpse.) The game can be saved right before picking up the bolts, thus making them always retrievable after a quickload or two.

Locations
If the player speaks to O'Malley on the first visit to Detroit, he will tell them that a crossbow (The murder weapon that killed an unnamed drug dealer) is hidden in the trash across from the Chiron Building. At the end of the quest, Jenny Alexander will ask for the murder weapon back. (The player can refuse but this will hurt their chances of winning the case.)
 * Bought from various blackmarket vendors.
 * Inside the porter building at Belltower Dock Yard.
 * Inside a storage room behind a level 4 panel, near the bot patrol, in Singapore / at Omega Ranch.

Behind the scenes

 * This weapon was probably inspired by the Twinbow II crossbow.
 * This weapon uses Guillaume Tell Golden Arrows. The bolts's brand name was likely inspired by the Swiss folk hero, William Tell, a legendary marksman who uses a crossbow to eliminate his targets.