Tractor beam emitter

A tractor beam emitter was a starship component that projects a graviton beam called a "tractor beam". This graviton beam was capable of either attraction or repulsion.

The shuttlebays aboard Federation starships each have a tractor beam emitter mounted near the shuttlebay in order to guide shuttlecraft in. In addition, each shuttlebay has a tractor beam emitter mounted within. 

In 2377, the USS Voyager's Emergency Command Hologram escaped from Quarren ships by firing on their tractor beam emitters. .