The compact laser deluxe was a small, but powerful laser weapon.
Captain Jack Harkness tried threatening the Unon with it. (COMIC: Weapons of Past Destruction)
Its compact dimensions were demonstrated when Jack was able to draw it on and surprise Trin-E and Zu-Zana despite being completely naked at the time, using the weapon to blow their heads off after they threatened him. Jack refused to elaborate on where he'd been hiding it other than it being somewhere "you really don't wanna know". (TV: Bad Wolf)
The compact laser deluxe was also seen when John Hart surrendered his weapons. (TV: Kiss Kiss, Bang Bang)