The Bosch Custom Case System Box is a clear storage box that clips into the cases, making it a secure place to store screws, bolts and other accessories. The Custom Case System is compatible with Driven Bits, providing the best case for the best bits. The durable, well-designed case houses clips that allow bits to tilt-in/tilt-out. This makes it convenient and easy to access to the bits. This customizable organization system helps user increase productivity by reducing time searching for the right bit.