Features 1、3 controlling knobs and 1 switch are accurate and high sensitive. 2、Oct1 knob: Adjust the volume of the first voice of octave. 3、Oct2 knob: Adjust the volume of the second voice of octave. Specification Features: Full metal shell, durable and exquisite. 3 controlling knobs and 1 switch are accurate and high sensitive. Oct1 knob: Adjust the volume of the first voice of octave. Oct2 knob: Adjust the volume of the second voice of octave. Dry knob: Adjust the volume of dry signal. Mode switch: Switch between top(+1 OCT and +2 OCT), both(-1 OCT and +1 OCT) and bottom(-1 OCT and -2 OCT) mode. Output jack: 1/4" mono audio jack for signal output. Input jack: 1/4" mono audio jack for connecting guitar. True bypass footswitch and lever designed to prevent stamping on operation knobs. Specifications: Model: AROMA AOS-3 Effect: Polyphonic Octave Material: Aluminium Alloy Input Impedance: 470K Ohms Output Impedance: 100 Ohms Current Draw: 68 mA Power supply: AC Adapter 9V DC (not included) Item Size: 9 * 3.8 * 4.8cm / 3.5 * 1.5 * 1.8in Item Weight: 151g / 5.3oz Package Size: 12 * 7 * 6.5cm / 4.7 * 2.7 * 2.5in Package Weight: 246g / 8.6oz Note: Please use the 9V power adapter whose polarity is positive pole outside and negative pole inside. Otherwise, the product may not work properly. Package List: 1 * Guitar Effect Pedal 2 * Adhesive Tape 1 * User Manual (English & Chinese) 1 * Hardcover Box Package List 1 * Guitar Effect Pedal 2 * Adhesive Tape 1 * User Manual (English & Chinese) 1 * Hardcover Box