The nek'sed, or lightning cannon, was an energy weapon developed by the Goa'uld Empire. It was a two-pronged device the size of a Death Glider cannon. The nek'sed was attached to a portable Naquadah generator. When activated, the device hummed and electrified the air between the two prongs. When firing, a blue arc of electricity fires from the end of the cannon and would strike the target location with such a massive amount of energy that even the toughest of Jaffa would be killed.
The weapon was a suitable defensive weapon as it killed groups of enemy infantry, particularly Jaffa whose metallic wearing armor conducted the electricity even further. Goa'uld engineers designed the weapon for the System Lords. However, it was rarely used due to its size and the need for a portable Naquadah generator. Furthermore, Jaffa warriors tended to favor close quarters combat, and the use of the weapon would kill both loyal and enemy Jaffa alike. (RPG: "Fantastic Frontiers: Stargate Season One")