The Ultra-Mech Pad is a device in Ratchet & Clank, Going Commando, Size Matters, and Secret Agent Clank. It is a pad on the floor emitting a shiny glow from its center, capable of enlarging robots, developed by the Ultra-Mech Scientist on a contract with the blarg, which transforms Clank into Giant Clank.
Ratchet & Clank
The Ultra-Mech Pad was developed by the Ultra-Mech Scientist in the robot factory, Quartu, for the blarg, to be used for their Ultra-Mech Unlimited robots. The Scientist was unaware that Chairman Drek was responsible, and tried to destroy it after learning this. Later, when Ratchet and Clank found him during "Find out more about the Ultra-Mech", Clank offered to enlarge himself to destroy the blarg's Ultra-Mech Unlimited robots, and the scientist said that Clank could be transformed back afterwards "in theory". After destroying them, the Scientist recalibrated the pad's controls to allow only Clank's specific circuit pattern.
Ratchet and Clank later found a Pad in the Kyzil Plateau, Veldin, used to enlarge Giant Clank and fight blarg forces, before reaching Drek in his Ultra Supreme Executive Chairman Drek-Mech. After dealing some damage to the mech, Drek used it to revert Clank back to his smaller form.
Ratchet and Clank found an Ultra-Mech Pad in the testing facility on planet Dobbo during "Explore the testing facility". The Mathematician appeared adjacent to this pad, and invited challengers to the Lunar City on Dobbo's moon, where challengers had to compete before being allowed entry into the Megacorp Games. Clank recognized the pad and used it to transform to Giant Clank, and defeated the challenger, the Thug Leader in his own mech, in "Defeat the Thug Leader", afterwards proceeding to the Megacorp Games.
Ratchet and Clank found two pads allowing Clank to transform to Giant Clank, where he fought several technomite ships in orbit.
Secret Agent Clank
Clank used an Ultra-Mech Pad to transform to Giant Clank and follow Klunk after he lost his ship.