The Marshall BB-2 Bluesbreaker II builds upon the original Bluesbreaker pedal by adding switchable modes, essentially making this two pedals in one. "Boost" mode is a standard clean boost, perfect for when you want to hit the front of your tube amp just a little bit harder and not change the sound of the amp significantly. Flip over to "Blues" mode, though, and you'll get all the harmonic saturation that makes vintage non-Master Volume Marshalls so desirable. If you're constantly gigging or on the road, you'll find comfort in the wholly sturdy solid metal casing, protecting the BB-2 from the bruises and bumps that come with the territory of being stomped on night and day.