I own one of these (paid $210 on ebay). It is actually an "active" (i.e., has to be plugged in to an ac outlet) MC headamp (not a phono stage and not a transformer), with 2 gain settings, 24 or 32 db; the MM setting provides no gain, so on that setting the unit is effectively doing nothing. All 3 settings mentioned are via a large rotary knob on the front; there is no on/off switch, it's either plugged in or not, indicated by a red led on the front The piece is about 3" high, 4" wide, and perhaps 10" deep (These are approximate.) Mine has a silver faceplate and the box is a light gray. This unit sounds great with Denon cartridges that tend to be a bit rich and laid back, because it seems to increase dynamics, e.g., the 103D (Of course, the sound will also be affected by whatever phono stage you use). When I switched to an Ortofon Kontrapunkt "a" cartridge, which is a totally different animal, however, the sound thinned out and I ended up switching to a different headamp, the McIntosh MCP-1. I prefer this new setup in every respect, but under the right circumstances the Denon can sound just fine.
