This mass-produced model of the Gunbuster, officially named "Sizzler," is the Earth Empire Space Force's main mass-produced machine, replacing the RX-7, which was completely powerless against space monsters.
It eliminates the combining function and is almost entirely based on the Gunbuster, except for being a single-seater. Like the Gunbuster, it uses direct motion, so it is classified as a machine weapon.
Each unit has a black, white, or silver pattern color scheme, and there are also prototypes in the same colors as the Gunbuster (none of which have appeared in SRW).
Its equipped Star No. 3 Degenerate Reactor can generate up to 10^26 per second, roughly equivalent to the nuclear reaction of the sun.
According to the spin-off "Sizzler Project," the Gunbuster's functions, which had to be made larger due to the incorporation of new technology, were revised to make it smaller and lighter, making it more practical than the Gunbuster. The engineer in charge stated, "It's a common lie in robot anime that the earlier prototype has better performance," "The Gunbuster is simply over-specced," and "There's no question about the Sizzler's superiority as a practical machine," which shows that, like the Dragoon, it was set up as "a mass-produced machine that is stronger than the prototype."
In the final episode, it was deployed as the main force of the galactic center assault fleet, and engaged in battle against a space monster as a carrier-based aircraft of the Eltrium. Unlike the RX-7, it was able to fight on equal terms with the space monster, but in the end, over 10,000 units were lost.