Compact laser deluxe
From Tardis Wiki, the free Doctor Who reference
The Compact Laser Deluxe was a powerful laser weapon that was extremely small though still quite noticeable when pointed at one.
Its compact dimensions were proven when Captain Jack Harkness stored it away somewhere "you really don't wanna know", presumably in his backside, in case of emergencies. Its only known carrier was Jack Harkness. He used one to destroy the robots Trin-E and Zu-Zana. (DW: Bad Wolf)
