Cloaker

A cloaker was a small cloaking device that could be used by an individual.

In 2371, Quark discovered a prototype Romulan cloaker and used it to roam about Deep Space 9 unseen. After the experience of being invisible was not as he hoped, the Romulan Katann mentioned that the radiation given off by the cloaker would have been harmful to a Romulan, but should just make Quark ill for a few weeks. 

In 2372, the Romulans lent the experimental cloaker to Starfleet for Worf, Kira Nerys and Odo's mission to the Gamma Quadrant.