There is no significant difference between the sound of a plastic kazoo and a metal one. But a metal one is actually more fragile, you can easily punch through the membrane, effectively ruining the instrument (in this, plastic one, the hole is protected by a plastic 'cross'). Then the metal itself is cheap (no surprise here) and poorly assembled. And a plastic kazoo is simple and sturdy. And few cents cheaper. Plus you can pick from a variety of colours. I pick this one as an ultimate kazoo!