A great underrated boost pedal, the MXR mini boost is the Micro Amp pedal circuit and the Echoplex preamp in the same pedal!
The Micro Amp circuit is controlled by the volume and tone knob on the top of the pedal, the Echoplex circuit has a mini pot that is preset inside for a combined huge amount of gain! The small footprint is terrific for preserving space on your pedalboard and I always left the pedal on and had it push my amp into overdrive using my guitar's volume control. Downsizing my rig a bit and this pedal is super clean and will be a big asset to it's new owner! Will consider shipping if you want to pay.....