Stun gun

The Stun gun, officially called the Buzzkill TND, is a weapon in Deus Ex: Human Revolution.

Use
The Buzzkill Threat Negation Device (TND) instantaneously knocks individual targets unconscious at close range. Also useful on bots and electronic devices to confuse them temporarily, the stun gun is made by Mustang Arms Ad-Tech Ltd. As both are ranged, non-lethal firearms which can only load one shot at a time, both the stun gun and its cousin the PAX-22 fill a similar niche, albeit at different ranges. The small stun gun is only useful at short-shorter medium ranges, but can affect non-human targets. With its scope, the PAX-22 is best used at sufficient range for the scope to not interfere with aim.

In-game Description
The Buzzkill Threat Negation Device (TND) is a single-shot, non-lethal firearm that uses an intense electroshock discharge to render targets unconscious. While easy to conceal, the weapon has a short range, slow firing cycle, and lengthy reload time. It is primarily for use against organic targets, but is also effective in temporarily disabling security camera, turrets and bots.

The stun gun is best reserved for situations where patrolling enemies must be incapacitated quickly, but the player is too far away for a takedown. As takedowns freeze time and render the player temporarily invulnerable, a one-two punch of a takedown on one target, then a quick shot with an already equipped stun gun on another target is a quick and easy tactic for incapacitating two enemies at once, useful for when pairs of enemies are standing within close range, a common occurrence.

Locations
The stun gun can be first received from David Sarif during the first mission, by requesting a close-range nonlethal weapon.

A stun gun, along with some darts, can be found in a locked lot in Detroit. Hacking capture level 2 is required.

Note
The Buzzkill Threat Negation Device cannot be upgraded.