Pedal has been on a board at church for the better part of a decade and in storage since. It shows obvious signs of use but appears to be working just fine.

From the Mad Professor website:

LITTLE GREEN WONDER is a high headroom overdrive/booster pedal for an electric guitar. It has a special EQ curve and low complexity with high output that sounds great with both single coil and humbucker pickups. LGW works very well even with amplifiers that have a complex distortion pattern or a bright tone and it stacks extremely well with other pedals.

CONTROLS

• DRIVE, to adjust distortion, sustain and
harmonic content.
A good starting point for this control is a bit
below center (eleven o’clock).
• BODY, sets the frequency range of distortion.
Turn CCW for more bass and low-mids with
slight treble boost. Turn CW to get just a slight
treble increase.
• VOLUME sets the balance between processed
signal and non-processed.
USE AS A BOOSTER:
Set Body near full CCW and Drive in full CCW.
USE AS AN OVERDRIVE:
Start from Drive 12 o’clock, Vol 11 o’clock, BodY
11 o’clock. turn BodY cW for a brighter tone.
USE AS A HEAVY DISTORTION:
Body full CCW setting and Drive at full CW gives a fairly heavy distortion with a slightly soft edge.

Power requirements:
LGW uses standard 6F22 9V battery or 9 - 18V dc battery eliminator.