The Guul is an atmospheric subflight lifter used by ZAFT. Its purpose is to grant flight capabilities to normally land bound mobile suits within Earth's atmosphere. It is remotely controlled by the pilot of the mobile suit it carries. The Guul possesses enough thrust to keep itself and one mobile suit, which stands atop the Guul, airborne, while performing aerial maneuvers. It is used in conjunction with ZAFT's general multipurpose mobile suits ZGMF-1017 GINN, ZGMF-515 CGUE, ZGMF-1000 ZAKU Warrior, and their variants. They are also compatible with the G Project Gundam units ZAFT stole from the Earth Alliance.
Although it is not designed to enter combat without a mobile suit, the Guul is lightly armed with two missile launchers on its wings. It can also fold its wings, allowing the Guul to more easily be stored when not in use.