Specifications: Model: 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