Comes with a box, one knob was swapped. A favorite pedal of J. Mascis of Dinosaur Jr, the Box of Rock is a clean boost and distortion housed within one unit. Designed to emulate the tones of a classic overdriven Marshall, the Box of Rock sports separate footswitches for boost and distortion, a streamlined four-knob interface, and Zvex's signature "Distortron" distortion circuit.