The NerveGear is a streamlined helmet coated in dark blue. At the back is a long pad with a wire the same color as the NerveGear stretching out of it. It also has a battery and internal memory to store data from the games. 30% of the NerveGear's weight is from its internal battery. The headgear features three LED lights on the front rim that indicate power, network connection, and brain interface status respectively. If the brain interface status light switches to red, this signifies that the user's brain has been rendered non-functioning.
The NerveGear's high-density microwave transceivers are capable of accessing the user's brain, allowing it to send fake signals to the five senses of the user. The transceivers are not only capable of inducing fake sensory signals but can also block every movement command from the brain to the body, preventing the player from moving their body while in FullDive to avoid injuries. The transceivers are also capable of blocking sensory information from the body to the brain, thus, while using it, the player is completely insensate to the physical world. The NerveGear is able to destroy a person's brain by emitting high-powered microwaves, shutting down one's vital processes, and Sword Art Online's (SAO) operating system has been programmed to do so if the player's Hit Points are reduced to zero. Despite the exact method that kills a player being disclosed in the story, some of the signs left behind in the brain are cerebral hemorrhaging and arterial occlusion. The NerveGear is equipped with a new generation diamond semiconductor central processor.
At the time of the Sword Art Online beta test, there were about 200,000 players in possession of a NerveGear. Half of them applied for the beta test, while only 1,000 of them were actually invited to participate in it.
After the events of the Death Game incident, Argus no longer produced new NerveGear units, and most users instead used RECT's replacement for the system - the AmuSphere, which has significantly less powerful transceivers; it is thus incapable of doing harm to a player, but cannot completely eliminate normal sensory input.
Kirigaya Kazuto is one of the few VRMMO players who used a NerveGear even after the SAO incident, though this was likely due to time and monetary constraints in getting an AmuSphere, as he wanted to check out the possibility of Asuna being trapped in ALfheim Online. Eventually, even Kazuto switched to using an AmuSphere after the ALO incident.
To use the NerveGear, the player wears the game console over the head. Then it is recommended for the player to find a comfortable position to station the body, commonly a bed. Afterwards, the game will load upon utterance of the initiation words, "Link Start".
- Sword Art Online beta testers
- Sword Art Online players (Kayaba Akihiko used a modified version of the NerveGear)
- The NerveGear's high-density microwave transceivers can determine what the user's face looks like.
- In the Accel World series, written by the same author as Sword Art Online, volume 4, chapter 8 mentions an unnamed VR machine that is similar in background to the NerveGear. Episode 22 of the anime adaptation of the series shows the unnamed machine as a NerveGear.
- Kazuto and Gabriel Miller are two of the few people who still possess a NerveGear after the SAO incident. Kazuto was able to keep his hardware due to negotiations with Kikuoka Seijirou to let him keep it even though all copies of the NerveGear were meant to be disposed of.