This Lab #18 is a dual Overdrive based on the AnalogMan version of the Blues Breaker, the King of Tone.
This pedal have a onboard 18VDC charge pump (no need to wire it to a 18VDC outlet anymore), dual independent overdrive circuit with internal switch for Hard and Soft clipping of each channel. Internal trimpot for the presence control of each channel.
Enclosure is a 1590BB. Currently wired with 1n914 diode on socket (you can put whatever you want there) and JRC4580 chip.
For the production model, have a look here.