Emergency transport unit

From Memory Alpha, the free Star Trek reference

The Emergency transport unit is a device developed in 2379 by Lieutenant Commanders Data and Geordi La Forge. This small, cylindrical device was designed to provide a single one-direction transport for one individual, thus allowing him or her to escape a potentially dangerous situation.

The first successful field test of the emergency transport unit occurred during the Battle of the Bassen Rift, when Data used the prototype to beam Jean-Luc Picard to the USS Enterprise-E before destroying the thalaron weapon aboard the Reman warbird Scimitar. (Star Trek Nemesis)

Also see: Emergency transporter armband