It's made by the same guys who made the original Guitar Silencer and Hush for Rocktron.
The Guitar Silencer is a good unit as well, but a touch outdated. It's prefered by guys who want hard cutting full stops (ie, Fear Factory) as the gate cuts so hard compared to modern "transparent" units.
The Rocktron Hush C and Super C seem to be getting mixed reveiws lately....
I use the Hush circuit in my Rocktron IntelliPitch and the gate in my G-Major. Both work very well and my amp is dead silent at idle with no transient noise on any gain setting at any level.