The Atanik armband was a technology, developed by the Ataniks, which greatly increased all of the natural abilities of whoever wore it, including granting the wearer unprecedented speed and strength.
These armbands worked by releasing a virus into the wearer, allowing them to 'interface' with the wearer's body. However, the effect of the armband was only temporary as the immune system of the wearer would eventually eradicate the virus and create a permanent immunity to it. When this occurred, the armband would simply fall off of the wearer and they would be unable to utilize it again.
This aspect of the device ultimately lead to the downfall of the Atanik civilization; the Atanik warriors developed an immunity to the virus, causing the armbands to become ineffective, thus leaving them vulnerable to attack. Long after the fall of the Antanik civilization, several armbands were discovered by the Tok'ra Anise in an archaeological survey of the Atanik planet.
The armbands are ineffective on the Goa'uld, Tok'ra, and Jaffa, likely a result of their symbiotes. Furthermore, the armbands are incredibly resilient, being virtually irremovable once placed on the wearer's arm. (SG1: "Upgrades")
Carter was able to see well in the dark without the presence of a light. She was also capable of writing a thousand-page book on wormhole physics in under two hours while both Daniel and Jack could read books in mere seconds. The armbands also caused erratic behavior resulting from an increase in various hormone levels, which created a feeling of intoxication in the wearer. As such, these devices impaired the team's judgment and, in some instances, made them extremely aggressive; so much so that they started a brawl at O'Malley's Bar & Grill after one of the customers there insulted Daniel, calling him a "geek". Furthermore, to compensate for these abilities, the metabolism of the wearer is increased to match the increased energy needs of the body. This resulted in each member of SG-1 being able to eat as many as four large steaks in a single meal.
When SG-1 learned of a prototype mothership being built by Apophis, the team defied orders, leaving the SGC unauthorized via the Stargate, and used the armbands to overpower the dozens of Jaffa guarding the ship construction facility with ease. While in the facility, however, the team began developing an immunity to the armband's virus, ultimately causing the armbands to become useless. It was only the timely arrival of Teal'c which saved the team from death. (SG1: "Upgrades")
Behind the scenes
- Dr. Daniel Jackson, as the armband takes effect upon him, reads the inscription, which he translates as "With great power comes great responsibility". This is the heroic code put forward by Spider-Man. Anise adds a corollary - "And the ability to effect great consequences".