The Shadow SH Five Plus is a five band EQ with volume control. It has a phase invert switch to minimize feedback. In the "OFF" position the EQ-shape switch creates a flat frequency curve. In the middle position of the EQ controls and the "ON" position the bass and treble are boosted and the mid frequencies are cut to create "V" shape at mid position of the tone controls. The 9V battery is under the preamp and is easy to access by lifting the preamp out of the case. Fixing screws are not locked into the wood, instead, they are fixed into plastic plugs under the wood. It is totally shielded and has zero hum.