This is an original HO, not the later versions after he sold the company. It has two channels for to amps, going to the same speaker(s). Each amp gets attenuation. Foot switch changes the amps used. Amps are set to 16 ohms, speakers can be 4, 8 or 16 ohms (since re-amping is solid state). Comes with wiring diagram drawn by Mr. Ho.
I'm also selling an Ultimate Attenuator, which is a single channel re-amper, also posted on craigslist.