Feature: 1. Compact and light-weight design, easy to carry. 2. Built-in distortion effect. 3. Designed with 3 adjuster: Level, tone, gain. 4. 0.25in plug, just plug into guitar jack, no need of installation. 5. Powered by two AAA 1.5 alkaline battery (not included). Specification: Features: Compact and light-weight design, easy to carry. Built-in distortion effect. Designed with 3 adjuster: Level, tone, gain. 0.25in plug, just plug into guitar jack, no need of installation. Powered by two AAA 1.5 alkaline batteries (not included). Specifications: Color: Black Power: Two AAA 1.5 alkaline batteries (not included) Product size: 9.7 * 8.4 * 2.1cm / 3.8 * 3.3 * 0.8in Product weight: 44g / 1.5oz Package size: 16 * 13 * 2.8cm / 6.3 * 5.1 * 1.1 Package weight: 77g / 2.7oz Package List: 1 * Guitar Plug Headphone Amp 1 * User Manual (English & Chinese) Package List: 1 * Guitar Plug Headphone Amp 1 * User Manual (English & Chinese)