Stun rods are a type of stunner used by the Wraith.
Effect
These rods are two small sticks, which are small enough to conceal them into coat sleeves. To use them, one must touch together the two rods, which then emit a temporary localized stunning field in front of the device capable of rendering all humans in close proximity to the device unconscious.
History

After two Wraith cruisers were destroyed by the effects of the Attero device, Todd used such a device to subdue the bridge crew of the Daedalus in order to commandeer the ship after believing he had been betrayed by the Atlantis expedition. (SGA: "First Contact")
Notes

The Wraith stun rod has an area effect much like the Wraith bomb, but seemingly works on a smaller scale.