A Stargate is a device 6.7 meters in diameter which can instantaneously transport objects and certain inmaterial things through to another stargate through use of a wormhole based on contact. Its original design is theorized to be Gammetan, however is currently unknown. It was introduced to the Appearence inhabitants by the Gammetans, and then frequently used by the Yulairians.
Stargates are remotely accompanied by a Dial Home Device (often abbreviated DHD). On the DHD, there is an interface with nine text boxes and seven different keys. Each key is effectively a digit, ranging zero (0) through six (6). All nine boxes are for targetting stargates, however only the first three's functions have been determined (position on an X plane, Y plan and Z plane relative to the dialing gate). Distance is dealt on a seven-digit system, where
0 would be for the current position and
10 would be seven units away. Each unit is around 430,000,000,000 kilometers3 (aproximately 4.5% of a light year).
When the first three boxes have been entered, a button at the far right side of the interface can be pressed. Once this occurs, a ring plate would start spinning relative to the angle of the gate. When a certain symbol aligns with the first chevron (counting clockwise from the topmost symbol, the eighth), the shevron lights up. The gate would resume spinning and follow the same procedure for the second (topmost) chevron and then the third (first past topmost). If the gate cannot aquire a lock (id est there is no destination gate at the entered coordinates), the chevron lights will fade and the gate will become inactive. The interface would then become active once more.
Upon aquiring a "lock" with a destination gate, an unstable vortex will emerge from the gate and "kawoosh" in to one direction. The unstable vortex stretches around 10 meters. Any matter within that unstable vortex would be instantly vapourized. A few seconds later, the unstable vortex would submerge back towards the gate and form the "event horizon." Once this has occured, when matter passes through the horizon, it will be transported to the destination gate using wormhole technology. Sending matter from the destination gate to the origin gate would not work. The matter would simply be vapourized similar to the unstable vortex.