Humes & Berg 20" Fiber Gong Case (650). The Vulcanized Fiber material was developed many years ago to make Salesman sample cases. Humes & Berg took this material and made drum cases that quickly became the industry standard. They have been manufacturing Humes and Berg custom built Vulcanized cases for over 60 years. The reputation of our Fiber Cases for their Quality and Durability is accepted throughout the world. These cases are tough and withstand active use.