Metal Harmonica and Kazoo Set You will receive one of each - one metal harmonica and one metal kazoo Kazoo: Metal Kazoo, Childproof Safety Cap & Resonator, Edges Rounded to be Smooth and Safe, 4.75". Boxed with instructions and Kazoo trivia on box. For ages 5+ Harmonica: This 6" harmonica has a 10 hole construction in the key of C. Easy to play, it's an instrument that's fun to master for all ages. Metal and plastic construction. Boxed. Ages 3 and up.