The Lexo-Skel Suit 5000 was a combat exoskeleton created by LexCorp.
Designed to be piloted by a single man, the Lexo-Skel was a heavily armed and armored battlesuit that Lex Luthor touted as a weapon to end all wars. Secretly, Luthor had arranged to sell the battlesuit to the Regent of Kaznia, who planned to use it against his various political enemies. Because Kaznia was under a trade embargo, Luthor arranged the sale by staging a "theft" of the Lexo-Skel by John Corben during a public exhibition of its abilities.
As Clark Kent shrewdly observed, Luthor's "loss" was actually a win-win scenario: not only had he made a billion dollars from the secret sale, but he would undoubtedly be commissioned by the U.S. military to build an even bigger and better version, to counter the threat posed by the Lexo-Skel being in the hands of terrorists.
Based on Kent's suppositions, Lois Lane tracked Corben to a Kaznian freighter, where the battlesuit had been prepared for shipping. Superman arrived and quickly dispatched Corben's comrades, and Corben entered the battlesuit to give himself a fighting chance. Unfortunately for him, all he managed to do was to buy himself a few extra minutes (and wreak destruction over a significant sector of Metropolis), after which Superman rallied and quickly tore the suit to pieces, forcing Corben to surrender. The Regent, who had paid Luthor upfront, demanded a refund (though whether Luthor ever paid is unknown).
The Lexo-Skel caper was Superman's first confrontation with Corben, who would later become the cyborg Metallo, and also the first alert to Superman of Luthor's criminal activities.
Abilities and equipment
The Lexo-Skel was armed with a rotary cannon, a very large anti-armor cannon and anti-tank missile launchers. Jet packs mounted on the suit enabled it to make long, rocket-assisted jumps though it was not capable of true flight. It was also heavily armored.
Luthor's public relations representative boasted that it gave one man the fighting potential of an entire armored division.