Ultrasafe Transporter: Gadgetzan

The Ultrasafe Transporter: Gadgetzan is the latest in highly-safe Gnomish transportation. This little gadget will send you whisking through the Hyper-Never-Ether and land you with not even a bump at Gadgetzan! How can it go wrong?

Source
This item is made by engineers who have specialized in Gnome Engineering, and have a minimum skill level of 260.

The recipe is taught by, by the transport in Gadgetzan. He will teach you the recipe for free if you have 260 Engineering skill and are a Gnomish Engineer.

Background
A contingent of gnomes in Gadgetzan created this device in the hopes of reducing the air travel problems caused by frequent travelers to Tanaris. The transporter consists of two devices - a small, handheld actuator and a bulky, immobile pad big enough to accommodate a creature as large as a tauren. The pad utilizes chaos energy to weaken the fabric of space in its vicinity, allowing anyone activating one of the actuators to "pop" instantaneously from his present location onto the pad. According to the gnomes, this is a perfectly safe form of travel, as long as you follow each and every one of the safety procedures - which fill a 2-inch-thick manual. The rip in space caused by the transporter is extremely sensitive to other forms of space alteration. Objects that contain extradimensional spaces can't be sent through the transporter (they simply don't arrive at the destination and are never seen again, along with all their contents). Also, using size-alteration devices or magic disrupts the transporter. Thus attempting a world enlarger to reduce one's weight (or to bring along passengers) is not a good idea. Gadgetzan's pad was the first transporter created. Goblins have created their own version of the transporter technology as well. Not long after the gnomes put up a transporter in Gadgetzan, one was built in Booty Bay (which connects to Gnomeregan). Goblins have also built a transporter to Everlook.