A fictional transformable Mecha from the Kikou Souseiki Mospeada science fiction series from the 80s.
The AB-01 Tread heavy mecha is a 3 form heavy armed and heavy armored all-purpose and support variable Bomber designed to be connected with the Legioss.
It has 3 transformation modes: Armo-Soldier (Giant Robot), Armo-Bomber (Bomber/Heavy Spacecraft) and Armo-Diver (Gerwalk). The Tread can be connected in tandem with the Legioss mecha.
TR.EA.D. stands for "TRans EArth Deployment heavy transformable fighter".
In Real Life it was designed by Aramaki Shinji in the early 80s.