If you're looking for a great 2-in-1 Overdrive/Boost pedal, this gently used Keeley D&M Drive is a great choice. Use them independently or together for various shades of drive and boost capabilities. Here's what Keeley says about it!

The D&M Drive is the perfect storm of Drive and Boost.  The D&M offers a gorgeous sounding high-voltage Boost side which is designed to impart the perfect tone on any amp that needs to be pushed.  No longer will you wonder what the perfect clean boost should be.  As you roll things up, the drive morphs your tone into singing gold.  A sexy and smoothly saturated midrange voice appears which breathes confidence.  The Drive side offers everything you would want in a powerful gain stage.  From flat honest overdrive that is perfect for any set of chords to searing hot lead work with tons of sustain.  The Drive is the perfect counterpoint to the Boost.  Not only does each side of the pedal provide rewarding guitar tones, they can be used to stack together for an out-of-this-world experience.