This is a watch like device give to Time Agents working for the Time Agency. Captain Jack Harkness owns one of these, and uses it to try and catch up to the doctor after being left on Satelite 5. His attempt fails, proving that the accuracy of the watch is not 100%, as he lands on 1869, rather than the 2000 period. The Vortex Manipulator is housed within a Time Agency wrist strap along other tools such as teleportor, remote control and others.
The Manipulator offers a shield from the effects of the Time Vortex to its users, but doesnt offer a comfortable ride, as shown by Jack, Martha, and The Doctor in Utopia.