The StealthX was a smaller than the XJ-Series X-Wing. It featured equipment that hid the craft both visually and from sensors, though the craft's position was given away if proton torpedoes were used or if the pilot broadcasted over the comlink. The StealthX was used exclusively by Jedi, as the restrictions on comm usage made it nearly impossible for anyone other than a Jedi to coordinate with other forces.
A modification of the already formidable T-65XJ3 X-Wing Starfighter, the StealthX had a star-flecked body of irregular, matte-black fiberplast that rendered it almost invisible against a backdrop of stars. The third launcher had been replaced by a gravitic modulator designed to defeat mass-detectors, and its shields had been downgraded to make room for a suite of sensor negators. Even its fusial engines had been retooled to burn special tibanna isotope, whose efflux turned dark a milisecond after fusion.
The advanced R9-series astromech droids were assigned to assist the pilots with the special requirements of this unique craft.
I recently started playing X-Wing Miniatures and what really hooked me was seeing the finely detailed models of all the starfighters that I used to play with as a child. Some of the later waves featured starfighters from the expanded universe that I was unaware of and got me into researching other craft yet to be featured.