By the time the ERS Alternator was released in 1993, it was already obsolete. The Shaq Attaq, released that same year, was lighter, lower, and did away with ERS entirely. And Hexalite soon come. The ERS Alternator was still a great design, but it seemed to be a time traveler from 1989 or so. A context-free retro release would make such things irrelevant, but it's best remembered as a charming oddity.
Reebok ERS Alternator