No-one has ever made more famous chorus effects than Boss. While the CE-2 is the most famous, the DC-2 really found it's own cult following in the shoegaze universe in recent years and is certainly held in extremely high regard. It's driven by not one, but two bucket brigade modulated delay circuits, set out of phase with each other, paired with the dry signal, to create a room-filling, shimmering swirly wobble. The dual delays give the signal a more steady feel than a CE-2, which only used one delayed signal, so it's a brighter and more subtle sound. In stereo, it's extra glorious. The four radio buttons, unique to this pedal in the Boss universe, cycle through increasing levels of spaciousness: wilder and wider to the right. Famous users include Dream Theatre, Deftones and  The Cure. I found this explainer from Catalinbread's helpful: 

"Despite its drab aesthetics, the circuit was rather expensive to make and deceptively complicated, relying on two separate BBD-equipped delay lines to process its truly atmospheric textures. Featuring 13 ICs, including two BBD lines and two companders, the DC-2 is one of Boss’s most complicated compact pedals, if not the most. The key to the operation is the compander circuits that, for lack of space, compress the dynamic range of signal up front and expand it in the back, hence the name and the circuit’s lush, room-filling tonality."

Model: Boss DC-2 Dimension-C
Made: Japan, June 1986
Serial: 677100
Type: chorus
Power Input: vintage Boss ACA 12v AC power supply or 9v battery (supply not included)
Accessories: none

Condition notes: used, no major marks. Tested and fully functional.
Overall: very good condition (8/10)