A thunder drum is a gourd with the bottom cut off so a drum head and spring can be attached. When the spring is wiggled, it vibrates the drum head, which in turn creates sound waves inside the gourd. The gourd amplifies the waves and releases it through other holes in the gourd and sounds like thunder. Each drum reverberates differently. There are many variables that make up the drum's tone. such as: the size of the gourd, the size of the drum head or opening, the shape of the gourd, the placement, shape, and size of the holes in the drum, and the smoothness of the inside of the gourd. Please let me know if you want me to send you a voicemail. If you are interested in any of my products in a different colour variation or want to order something what is not available in the shop at the moment - please contact me - I can make the custom order for you. Everything here is unique, it's mine own design and it's fully made by hands. Hopefully you'll find here something unusual for a gift or just to treat yourself. DIMENSIONS: height: 26cm / 10 inches width: 26 cm / 10 inches