Attach this voice changer to your key chain and you can change your voice whenever you want because you'll always have it with you. This is the smallest voice changer in the world. It measures less than two and a half inches tall and less than one and a half inches wide! Whether you using your phone at home, your cell phone, or a pay phone no one will be able to recognize your voice. Simply place it over the phones mouthpiece, adjust the hi/low setting, and speak normally. Great for fooling your friends or to protect women and children when home alone. Simple to operate. Battery included. 2.5" x 1.5" x 0.5". Only 0.5 oz.