Brian does good work. This is an amp-like and rich take on the Plexi- genre. The seperate 'pre-gain' switch and knob means you can shoot for more JCM800 style tones with an extra gain stage, or turn it off for a more 70s style Plexi sound. 

Model: Wampler Plexi-Drive Deluxe Overdrive
Made: USA, recent model
Type: overdrive, Marshall style
Power: standard 9v DC negative supply (not included)
Switching: true bypass
Equivalent new street price (approx): n/a (discontinued)
Mods: none
Accessories: no box or manual
Condition notes: used, no major marks, fully functional. Overall: very good condition