The Electro-Harmonix Headphone Amp goes anywhere and delivers a musical quality and attitude that defines the spirit of Electro-Harmonix. As uniquely musical as it is portable, the ultra-light Headphone Amp let's you practice as loud or funky as you want - Ultra lightweight and ...The Electro-Harmonix Headphone Amp goes anywhere and delivers a musical quality and attitude that defines the spirit of Electro-Harmonix. As uniquely musical as it is portable, the ultra-light Headphone Amp let's you practice as loud or funky as you want - Ultra lightweight and portable - Designed specifically for musical instruments - Get the character sound of your live instrument - Handles high gain pedal board input delivering your favorite tone and definition - Super quiet - Battery included, Headphones are NOT INCLUDED