FILTER/ENVELOPE PEDAL Envelope Filter (Auto-Wah) effect pedal. For guitar or bass. Controls: Level (controls the sensitivity of the filter) and Range (filter-sweep, controls the range of motion). Voice Up/Down, to select the part of the filter that you want to emphasize: Up (guit), Down (bass). Fully analog. Classic funk sounds that react to attack dynamics. True Bypass. Metallic chassis. Blue power LED. 9v battery. or optional feeder. Dimensions: 11.9 x 6.7 x 5.7cm. Weight: 281g.