Reverb effector, silver design, with a wooden case. - Model name: HOLY GRAIL REVERB Thank you for viewing. Along with BOSS DS-2, ce-1, Ibanez wh-10, and mxr micro amp, this is one of the essential effectors for the John Frusciante sound. It is a specification that the dry volume decreases when the knob is turned up. Due to the vintage nature of the item, no claims and no returns are accepted to prevent parts swapping.