It is very simple really, a half size case to fit 5 rolls of 35mm film. Just what the doctor ordered.
The cases are made from a durable and tough plastic, that will keep your films safe from the elements, but most importantly from light. They are lightweight and small enough that you can fit into your bag without taking up too much space.
The dimensions are L 136mm x W 31mm x H 50mm
For more info check here.