Gnomish Gravity Well

A Gnomish Gravity Well is a device created by Engineers. Using it will simply cause your character to jump up in the air a little higher than it is able to jump. The cooldown is however slightly shorter than the time it takes to fall back down, which means it's possible to use it in mid-air to get higher and higher by spamming it. It will however "stop" going upwards at a height somewhere at 50-60 yards. Using the device will always cause your character to jump straight upwards - as such, using it will also remove / stop any effects which causes your character to move in any other direction. It can only be used with players with Gnome Engineering.

This device cannot be used while in combat or in the following locations:
 * Non-flying zones
 * Instances
 * Scenarios
 * Battlegrounds
 * Arenas

Source
This item is created with Gnome Engineering (500); taught by trainers.

Uses
While appearing to be rather useless (as with most engineering devices), there are actually a few things this device is good for:
 * It's still possible to use abilities like Disengage and Rocket Jump to move another direction than upwards after you've gotten up in the air. It's furthermore possible to combine this with an effect which slows falling speed - such as Slow Fall (ability), Levitate, Parachute Cloak or Flexweave Underlay - to cause your character to move rapidly to or away from an area.
 * It works below water, which means it can be used to quickly reach the surface to prevent drowning.
 * As it "resets" falling speed as well, it can be used to prevent falling damage, if it is used shortly before the player hits the ground.
 * Its ability to halve movement speed can also be used to prevent your character from moving too far on areas where it's hard to control movement speed. On "slippery" areas, where the character will slide until it lands on something it's possible to walk on, for example. This can be useful when trying to reach normally inaccessible areas. As such areas are often reached by using rocket boots, the Gravity Well can also be used to halt movement to prevent the boots from making your character run too far.