Còi màng rung (Membrane Whistle)

To assemble a membrane whistle, you will need a flexible material such as a balloon or a silicone glove (it won't work with regular plastic wrap). Simply cut a piece of the balloon to the size of the whistle's bottom part and put it together. It's not difficult.

Important notice: the membrane must be stretched, otherwise the whistle will not work. The models have two sizes of the whistle's bottom part for thicker and thinner membranes.