This is fantastic, truly. The left side is a reverb, with some awesome options: reverse reverb, octave-up shimmery goodness, bloated hall sounds... lovely. The right side is a Muff-style fuzz, with a couple of EQ curve options to get it talking to your guitar just right. Send the fuzz into the reverb, and you get sensible, GIlmour-ish legato goodness. Push the button and send the reverb into the fuzz, and you get enormous gloomy wailing shoegaze dirges worthy of My Bloody Valentine. Being sad has never been so much fun. 

Model: Keeley Electronics Loomer 
Made: USA, recent. model
Serial: 03099
Type: reverb
Power Input: standard 9v DC centre-negative (supply not included)
Accessories: none

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