AT2u: 2HP dual passive attenuator (updated design)
20 in stock.
The 'u' stands for 'Updated'
An updated version of the AT2 dual attenuator - same functionality but the layout is a bit more user-friendly with jacks at the top and knobs at the bottom.
You can get the old version for cheap here, while stocks last.
WHAT DOES IT DO? It attenuates signals - think of it as a something like a volume control. However, since the module is passive it is only capable of attenuating, not amplifying, a signal.
If you want a module that can both attenuate and amplify, the vBST module will probably fit the bill (but is only a single channel)