Simply put, ZT amps are the loudest little amps in the world that can blow you away with what they can do - Small like your lunch boxes. Lightweight but loud, and a tone that satisfies top-level pros and is powerful enough for guitarists to gig with it.
ZT prides itself to give musicians ultra-compact, professional quality musical instrument amplifiers that are loud enough for live performance and small enough to never make someone say "man, I really don't want to have to carry that amp anywhere".