Features: Amplifier with Metal sound effect. Aux in jack lets you play along with your MP3 player. No matter you are in the college dorms or travelling， you can enjoy your music at any time without disturbing other people. Specifications: Sound effect: Metal Material: ABS MP3 input jack: 3.5mm Earphone jack: 3.5mm Powered by: 2 * AAA batteries (not included) Item size: 8.9 * 7.7 * 2.6cm / 3.5 * 3.0 * 1.0in Item weight: 41g / 1.4oz Package size: 15.7 * 11.8 * 2.5cm / 6.2 * 4.6 * 1.0in Package weight: 64g / 2.3oz Package List: 1 * Amplifier