JF-09 Tremolo Pedal uses the photoelectric tube circuit that is the same as the tremolo circuit on the older quality tube amplifiers. Intensity and Rate knobs make it easy to adjust the tone and vibe. This is a very well electrically designed and mechanically rugged pedal.Features:Use the photoelectric tube circuit， same as the tremolo of the old electronic tube amplifier. Intensity and Rate knobs make it easy to adjust the tone and vibe.True bypass design minimizes tone loss. Achieves the distinctive sound heard on so many classic recordings.Specifications:Model: JF-09Color: YellowMaterial: Aluminum alloyInput impedance: 1M��Output impedance: 1K��Running current: 7mASpeed range: 1Hz-20HzPower: 6F22 9V battery / DC 9V adapter (Neither included)Item size: 12 * 7.1 * 5.5cm / 4.7 * 2.8 * 2.2inItem weight: 290g / 10.2ozPackage size: 13 * 7.9 * 6.2cm / 5.1 * 3.1 * 2.4inPackage weight: 325g / 11.5ozPackage List: 1 * Effect Pedal1 * User Manual (English & Chinese)