Features: Compact and light-weight， easy to use and carry. Plug it in your guitar and enjoy the classic rock sound. 6.35mm plug， just plug into guitar jack， no need of installation. "Phones" jack to connect headphones， portable speaker， mixer， or recorder. AUX jack lets you connect an external audio device such as cellphone or MP3 player. 3 adjuster: gain， tone， vol. Comes with a USB cable for charging. Specifications: Color: Black Material: ABS Power Supply: Built-in rechargeable battery Working Current: 37mA Item Size: Approx. 7.5 * 7.5 * 1.2cm / 3 * 3 * 0.5in Item Weight: Approx. 33g / 1.2oz Package Size: 14 * 11 * 2cm / 5.5 * 4.3 * 0.8in Package Weight: 70g / 2.5oz Package List: 1 * Guitar Plug Headphone Amp 1 * USB Cable